Skull of frog is

$\begin{array}{1 1}(A)\;\text{Tricondylic}\\(B)\;\text{Monocondylic}\\(C)\;\text{Dicondylic}\\(D)\;\text{polycondylic}\end{array}$

Skull of all amphibians is polycondylic.
Hence (D) is the correct answer.