Question

Which corrects the shift in tense in this sentence?

Answer 1

A. swim because B doesn't make sense, neither does D. It could be A or C, but I'd pick A. I did this test before and I picked A, and got 80 % so good luck ;)

Answer 2

The answer is A: swim.

 They all like the beach, but none of them swim in the ocean.  After none of + a plural word (none of the shops, none of them etc.) it's possible to use a singular or plural verb, but a plural verb is more usual. None of the shops were (or was) open. Also, none + of  it's quite usual as a subject. B: past of swim is swam. C: past participle of swim is swum