Answer:
The error in subject-verb agreement is underlined below:
Jenny's favorite hiking trail wind from the base of Mt. Diablo up to the summit which offers breathtaking views of the surrounding area.
Step-by-step explanation:
Although the sentence above has quite a long subject - "Jenny's favorite hiking trail" - we can easily pinpoint which word is the most important in it: "trail". All the while, the sentence is talking about a trail. Therefore, the verb that follows the subject needs to agree with "trail", which is a third-person singular word.
That is precisely where we have an error. The verb "wind" is not in its singular form. In the present tense, the singular form of verbs ends in -s, -es, or -ies for the third person. In the case of "wind", it should be "winds". Therefore, the correct agreement would be:
- Jenny's favorite hiking trail winds from the base . . .
The rest of the sentence is alright.