A Multiple Choice Test Consists of Seven Questions with Five $\left(\begin{array}{l}7 \\ 3\end{array}\right)\left(\frac{3}{5}\right)^{3}\left(\frac{2}{5}\right)^{4}$

A multiple choice test consists of seven questions with five choices each. If a student guesses on all questions the probability that a student gets exactly 3 correct answers is given by

A) $\left(\begin{array}{l}7 \\ 3\end{array}\right) \left(\frac{3}{5}\right) ^{3}\left(\frac{2}{5}\right) ^{4}$
B) $\left(\begin{array}{l}7 \\ 5\end{array}\right) \left(\frac{1}{3}\right) ^{5}\left(\frac{2}{3}\right) ^{2}$
C) $\left(\begin{array}{l}7 \\ 5\end{array}\right) \left(\frac{1}{5}\right) ^{3}\left(\frac{4}{5}\right) ^{4}$
D) $\left(\begin{array}{l}7 \\ 3\end{array}\right) \left(\frac{1}{5}\right) ^{3}\left(\frac{4}{5}\right) ^{4}$