单选题 The writer comments on Stem's investigation and analysis in a ______ tone.

【正确答案】 C
【答案解析】从全文多处可看出作者对Stern的评价是正面的,例如;a writer able and willing to get this close is hard to find(第三段),She is a levelheaded investigator whose knowledge of the background of groups like these adds perspective to her interviews(第四段)以及a cogent analysis(倒数第二段)。