Identify the sentence in which the underlined clause is a noun clause. The number of competitions has increased every year since sled dog racing was organized.?

In the sentence "The number of competitions has increased every year since sled Dog Racing was organized," the underlined clause is "since sled dog racing was organized." This clause functions as an adverbial clause, providing context for when the increase occurred, rather than serving as a noun clause. A noun clause typically acts as a subject or object in a sentence.