Why was Five Forks such an important strategic position for Lee and his army?

I believe it is because of his rail links with the rest of confederacy.

It seems that you have missed the necessary options to answer this question, but anyway, here is the answer. Five Forks was such an important strategic position for Lee and his army because i t was the last escape route from Richmond. Hope this is the answer that you are looking for. Have a great day!