Comma after "was"?

Hey, everyone,

I'm pretty knowledgeable regarding grammar, but sometimes, commas can really throw me. Thus, my question is this: which of the following sentences is correct?

Her answer was, "I'll have to think about it."

Her answer was "I'll have to think about it."

The "was" here is confusing me, because I know that commas generally come after verbs that introduce quotations, but I'm just not sure here.

Thanks!