Consider the conditional statement: $"$If a student studies diligently, then he will achieve good

grades." Which of the following options correctly represents the contrapositive of this

statement?

A$.$ If a student does not study diligently, then he will not achieve good grades.

B$.$ If a student achieves good grades, then he has studied diligently.

C$.$ If a student does not achieve good grades, then they have not studied diligently.

D$.$ If a student studies diligently, then he will not achieve good grades.