Tricky SAT Writing Question?

Question

the only question i missed on the practice exam...

Beginning photographers may choose from among several camera types, ______ best for their particular interests

A) of which there is one

B) one of which is

Correct Answer: B

I could tell from my ear that B was correct but why isn't B a comma splice? I see a indpt clause, subject-verb combination (one...is) without a conjunction. Yet choice A clearly is a subordinate clause...

Someone clear this up!!!!

Answer 1

I know why!

The prepostion ''of which'', disagrees with the verb. So the only correct is ''one of which''.

Answer 2

i would say B; because its the shorter answer (haha)

it may be very possible that the comma were to be a semicolon

and they made a typo

practice tests arent 100% free from mistakes.