(a): The countries did notnot have much of a choicemuch of a choice when it came to vaccines.
(b): The countries did notnot have much choicemuch choice when it came to vaccines.
Are the sentences above semantically identical? Are there any differences between them? Which one is more natural? I
I am particularly curious about whether these two expressions--much of a (countable noun) and much (countable noun) without an indefinite article--are always interchangeable.