Question

grammar, which is way more fun than i thought, is my best subject. restrictive nonrestrictive no added clause

Explanation:

A nonrestrictive clause provides extra, non - essential information and is set off by commas. In the sentence "Grammar, which is way more fun than I thought, is my best subject", the clause "which is way more fun than I thought" gives additional info about "Grammar" and is separated by commas, so it's a nonrestrictive clause. A restrictive clause is essential and not set off by commas, and there is an added clause here, so the other options are incorrect.

Answer:

nonrestrictive