Answer:
The sentence which could effectively be placed in a summary of Chapter 4 of Wheels of Change because it expresses a key idea objectively is:
A. In the 1880s and 1890s, female bicycle racers faced a variety of opponents, including males, horses, and an occasional dog.
Explanation:
Among the options provided, letter A is the only presenting information objectively, that is, without the interference of opinions, feelings, or biases the author may have. That is not the case with the other options. Option B speaks of doing something "foolishly"; option C speaks of preference and of "kind people"; and option D speaks of supporting those woman because of their bravery. Thus, options B, C and D express opinions and feelings, which are completely subjective.
I'm almost positive it's C