Question

Identify the sentence in which the underlined clause is a noun clause. Although small local races were held in the nineteenth century, a major sled dog race was not staged until 1908. The International Federation of Sled Dog Sports, which governs racing, was formed in 1986 to promote the sport. The number of competitions has increased every year since sled dog racing was organized. Whoever wants to enter into a sled dog race today has a choice of more than 3,000 competitions.

Answer 1

D. Whoever wants to enter into a sled dog race today has a choice of more than 3,000 competitions.

Answer 2

The correct answer is D. Whoever wants to enter into a sled dog race today has a choice of more than 3,000 competitions.
A noun clause is a type of subordinate clause which usually starts with pronouns such as what, that, who, whoever, etc. They act as nouns (usually as subjects) of the entire sentence. So, 'whoever wants to enter into a sled dog race today' is the subject of this entire sentence (but also a noun clause). The other sentences do not have noun clauses (A has an adverb clause, B has an adjective clause, and C has an adverb clause).