Answer:
I think the answer should be Women were worthy cycling racers.
Explanation: "Some did not support women racing" would not be the answer because it said nothing about people not supporting women racing. "Horses often beat cyclists in racing" I didn't read anything that said horses were better than women at racing. And "Bicycle racing was a popular sport", or course it was a popular sport in the passage, but it wasn't found in the quotation.