Question

The subject of a sentence cannot be a noun clause.
a. True
b. False

Answer 1

its false. it can be a noun phrase
e.g
the book belongs to Sara.
in this sentence "the" is determiner (article) used to highlight the specification of book (the subject in the sentence) which belongs to a specific person Sara.
together they (the and book) make a noun phrase.
hope you understand the thing

Answer 2

b. False
The subject of a sentence can be a noun clause.