The correct option is D that Tanya is a talented person- complement of a verb
A noun clause is a dependent clause that functions as a noun. It usually
begins with what, whatever, whom, that and other such relative
pronouns. A noun clause can act as a subject, object, predicate
nominative or object of a preposition, in a sentence.
A verb complement is a word, a phrase or a clause that is added to the verb to complete its meaning.
The
noun clause "that Tanya is a talented person" is a verb
complement; the verb "believe" sounds incomplete without a word or clause that complements it. The noun clause in C functions as a verb
complement, hence it is correct.
Option A is incorrect because it
isn't a noun clause nor is it the subject; it contains the verb "believe" and noun clauses do not contain the main verb.
Option B is
incorrect because it is a part of the noun clause; it isn't the object.
This sentence doesn't have an object because the verb is not an action
verb that can be directed toward something.
Option D is incorrect because 'talented person' is a part of the noun clause, it isn't the clause itself.