用dsolve函数求微分方程【图片】的解析解，正确的命令是（ ）. A. y = dsolve((D2y)^2+x*Dy=5*y) B. y = dsolve('(D2y)^2+x*Dy=5*y') C. y = dsolve('(D2y)^2+x*Dy=5*y', 'x') D. y = dsolve('(D2y)^2+x*Dy=5*y', 't')