SAT WRITING NEED HELP.

HEY GUYS !

Some scientists believe that mentally stimulating activities may increase the number of brain cells (available to replace if any ) are lost through aging. A. As it is B. Available to replace any that C. Available, which replaces any that D. Available, replacing if any. Correct one is B. I have never seen this kind of question on sat , so they look all correct to me. How do you know which one is correct and others are incorrect ? Thanks!

I think it’s a restrictive clause which makes up the meaning of the sentence so ‘which’ shouldn’t be used. Also B sounds better haha.

The verb “replace” needs a direct object, and the word “if” can’t be one, but “any” is a noun, so it can be a D.O.

Now i have got it . Thankss