That was the time when there was a hunger for foreign knowledge and foreign thought

Answer: Option B

Wish : feel or express a strong desire or hope for something that cannot or probably will not happen.
Appetite : a natural desire to satisfy a bodily need, especially for food.
Undesired : (especially of an act or consequence) not wanted or desired.
Generosity :: the quality of being kind and generous.
Hunger : a feeling of discomfort or weakness caused by lack of food, coupled with the desire to eat.

Synonym of Hunger is Appetite