The answer is B.

The sentence conveys that she resisted attempts by editors to make her descriptions more dispassionate and, therefore, requires a term that encapsulates her determination, commitment, and resilience in maintaining empathy and anthropomorphism. The logic here involves recognizing that the word used to fill the blank should convey a positive trait related to unwavering dedication.

Blank (i):
A. fickle: Fickle means changing frequently, especially in one's loyalties, interests, or affections. In this context, the sentence suggests that Jane Goodall was not fickle but rather determined and committed to anthropomorphizing the animals.
B. stalwart: Stalwart refers to someone who is loyal, reliable, and hardworking. This term accurately captures the intended meaning in the sentence, emphasizing Jane Goodall's unwavering determination and commitment to anthropomorphizing the animals she observed.
C. solicitous: Solicitous means showing concern or care for someone's well-being. While it conveys a positive trait, it doesn't quite capture the sense of determination and resistance described in the sentence.
D. pretentious: Pretentious refers to attempting to impress by affecting greater importance, talent, or culture than is actually possessed. In the context of the sentence, this term doesn't align with Jane Goodall's genuine and empathetic approach to studying animals.
E. whimsical: Whimsical means playful or fanciful in an appealing and amusing way. This term doesn't fit the context, as the sentence describes Goodall's determination and resistance to making her descriptions more dispassionate, which is a more serious and committed approach.