47. The best placement for the underlined word would be:

Answer and Explanation

Your Answer is

Correct Answer is D

Explanation

Item D: Put it before efforts to modify the noun, which means "single effort".

Item A: lonely "adj. Lonely", adjectives can only modify nouns, and must be placed before the modified nouns, not verbs.

Item B: After approach, modify the prepositional phrase over years, and adjectives cannot modify the prepositional phrase, which is wrong.

Item C: After the years, modify the prepositional phrase guided by of, which is wrong.