Phrase: There are ... more beautiful flowers in that garden.

There are ___ more beautiful flowers in that garden.
(A) many (B) much
Which choice is correct?

.
Which do you think? (Hint: ‘flower’ is a countable noun)…

I think either one is possible.
There are many flowers which are prettier/more beautiful.
There are flowers which are much prettier/more beautiful.

.
Yes, you can parse it both ways.

In other words:

  • There are many [more beautiful] flowers …
    OR
  • There are [much more beautiful] flowers …
    .

I think this sentence lacks context. We can’t pick the answer unless we know what the author had in mind when he wrote the sentence.
I like tests that consist of sentences that are part of a story, and you don’t have to leave much to guesswork, you know the meaning of each sentence (more or less) and answering the test questions boils down entirely to knowing English grammar.

.
Bad question. B didn’t even cross my mind.
.

.
I agree with both of you. In that sentence, the “much more” parsing seems pretty unlikely to me – even though I agree that it’s possible. The “much more” parsing might be more natural or expected in a context such as this:
“That’s only a minor issue. There are much more serious problems that need to be addressed right now”.

What do you think, MM?
.

.
Yes, that’s much more natural.
.