Answer: The most effective way to vary the sentence patterns in the passage is A. to begin sentences with different parts of speech.
Explanation: Beginning sentences with different parts of speech avoids repetitions, adds variety to a piece of writing and, at the same time, it gives place to a well-written text. Most of the sentences of the passage provided start with a noun ("pugs"); therefore, it is necessary to vary the sentence patterns and modify the text by including other parts of speech at the beginning of these sentences, such as adverbs, conjunctions or pronouns.