Finish the art critic's review of a very peculiar modern art exhibition by selecting the grammatically correct option.

The gallery featured works by several local artists, _____ sculptures were made entirely of recycled cheddar cheese.

The correct answer is two of whose.

We need a possessive relative pronoun to indicate that the sculptures belong to the artists. "Whose" is the correct possessive relative pronoun.

When combined with a quantifier, the structure is [quantifier] + of + whose + [noun].

"Several of which" would incorrectly imply the artists are objects, and "whom's" is not a real word.