According to the passage, Houston aimed his leg-islative challenge at the graduate and professional school level on the basis of the assumption that（）
During the 1930s National Association for the
Advancement of Colored People (NAACP) attor-
neys Charles H. Houston, William Hastie, James
Line M. Nabrit, Leon Ransom, and Thurgood Marshall
(5) charted a legal strategy designed to end segrega-
tion in education. They developed a series of
legal cases challenging segregation in graduate
and professional schools. Houston believed that
the battle against segregation had to begin at the
(10) highest academic level in order to mitigate fear of
race mixing that could create even greater hostili-
ty and reluctance on the part of white judges.
After establishing a series of favorable legal
precedents in higher education, NAACP attorneys
(15) planned to launch an all-out attack on the sepa-
rate-but-equal doctrine in primary and secondary
schools. The strategy proved successful. In four
major United States Supreme Court decisions
precedents were established that would enable the
(20) NAACP to construct a solid legal foundation
upon which the Brown case could rest: Missouri
ex rel. Gaines v. Canada, Registrar of the
University of Missouri (1938); Sipuel v. Board of
Regents of the University of Oklahoma (1948);
(25) McLaurin v. Oklahoma State Regents for Higher
Education (1950); and Sweatt v. Painter (1950).
In the Oklahoma case, the Supreme Court held
that the plaintiff was entitled to enroll in the
University. The Oklahoma Regents responded by
(30) separating black and white students in cafeterias
and classrooms. The 1950 McLaurin decision
ruled that such internal separation was unconstitu-
tional. In the Sweatt ruling, delivered on the same
day, the Supreme Court held that the maintenance
(35) of separate law schools for whites and blacks was
unconstitutional. A year after Herman Sweatt
entered the University of Texas law school,
desegregation cases were filed in the states of
Kansas, South Carolina, Virginia, and Delaware,
(40) and in the District of Columbia asking the courts
to apply the qualitative test of the Sweatt case to
the elementary and secondary schools and to
declare the separate-but-equal doctrine invalid in
the area of public education.
(45) The 1954 Brown v. Board of Education deci-
sion declared that a classification based solely on
race violated the 14th Amendment to the United
States Constitution. The decision reversed the
(50) lished the separate-but-equal doctrine. The Brown
decision more than any other case launched the
"equalitarian revolution" in American jurispru-
dence and signalled the emerging primacy of
equality as a guide to constitutional decisions;
(55) nevertheless, the decision did not end state-
sanctioned segregation. Indeed, the second Brown
decision, known as Brown H and delivered a year
later, played a decisive role in limiting the effec-
tiveness and impact of the 1954 case by providing
(60) southern states with the opportunity to delay the
implementation of desegregation.
A．the greatest inequities existed at the highest academic and professional levels
B．the separate-but-equal doctrine applied solely to the highest academic levels
C．there were clear precedents for reform in existence at the graduate school level
D．the judiciary would feel less apprehension at desegregation on the graduate level
E． the consequences of desegregation would become immediately apparent at the graduate school level
