A.
Insert the following code into the <head> section of the web page:<style type= "text/css">@import url('sheet1.css');</style>
B.
Insert the following code into the <head> section of the web page:<link rel="stylesheet" type="text/css" href="sheet1.css">
C.
Insert the following code into the <head> section of the web page:<style type="text/css"><link rel="stylesheet" type="text/css" href="sheet1.css"></style>
D.
The stylesheet document is referenced in the style attribute of each element to be styled with sheet1.css.