Translation:This is not an important subject.
I wrote "This is not an important topic" and it marked it wrong... =(
Why not "That topic is not important"?
I believe "that topic/subject" would be הנושא הזה rather than זה נושא . The phrase זה נושא means "this is a subject". (FWIW, I made the same mistake.)
Is, "This topic is not important" really wrong.