单项选择题

(    )
   A.    B.
   C.-cotx+sinx+C   D.cotx+sinx+C

A.174.24.96:6088/Latex/latex.action?latex=XGludFxsZWZ0KCBcZnJhY3sxfXtzaW5eezJ9eH0gKzFccmlnaHQpZFxzaW54PQ%3D%3D'
B.C.174.24.96:6088/Latex/latex.action?latex=LVxmcmFjezF9e3Npbnh9K3NpbngrQw%3D%3D'
D.E.174.24.96:6088/Latex/latex.action?latex=XGZyYWN7MX17c2lueH0rc2lueCtD'
F.-cotx+sinx+C