"In the backyard, the dog barked and howled at the cat" is an example of—

The correct answer is simple sentence.

A simple sentence consists of a single independent clause that contains a subject and a predicate, and conveys a complete thought. It can contain compound elements, such as a compound verb or compound subject, as long as there is only one independent clause.

Let's analyze the given sentence: "In the backyard, the dog barked and howled at the cat"

1. Prepositional Phrase: "In the backyard" (indicates location).
2. Subject: "the dog"
3. Compound Verb (Predicate): "barked and howled at the cat" (two actions performed by the single subject "dog").

Because there is only one independent clause (one subject performing a compound predicate) and no dependent clauses, this is a simple sentence.