What does the following Perl code $($$flag$>$$count$1$: $count$2)=0$ accomplish?

Question $15$ options:

A$.$ It assigns $0$ to either count$1$ or count$2$ based on flag

B$.$ It increments either count$1$ or count$2$ by $1$ based on flag

C$.$ It compares count$1$ and count$2$

D$.$ It checks if count$1$ or count$2$ is equal to zero