15. Choose the sentence with correct subject-verb agreement. A. Galilea, a union electrician, were on his way to Anchorage, 240 miles beyond Denali on the George Parks
Highway
B. There is many dangers for which Alex is not prepared.
C. Snowshoes or waterproof boots is necessary in the snow and ice.
D. Jim and Alex make light conversation while traveling along the Alaskan highway.

D. Jim and Alex make light conversation while traveling along the Alaskan highway.

Explanation:

Subject-verb agreement means the subject in a sentence must be of the same number as its verb. In other words, this means that if the subject is singular, the verb will be in the singular form. And a plural subject will have a plural verb.

Among the given sentences, sentence D uses the correct subject-verb agreement. The subjects "Jim and Alex" are plural, thereby making the verb in its plural form "make".

Sentence A uses the plural helping verb "were" for the singular subject Galilea.

Sentence B uses the singular helping verb "is" for the word "dangers" which is plural.

Sentence C also uses a singular verb for a plural subject.

Thus, the correct answer is option D.