Read this excerpt: we meet at a college noted for knowledge, in a city noted for progress, in a state noted for strength, and we stand in need of all three, for we meet in an hour of change and challenge, in a decade of hope and fear, in an age of both knowledge and ignorance. the greater our knowledge increases, the greater our ignorance unfolds. john f. kennedy, "john f. kennedy address at rice university on the space effort" what is the main idea of this excerpt from kennedy's address at rice university? a. ignorance is dangerous, and we must fight against it. b. the students at this university are some of the smartest in the world. c. we are about to enter a period of extraordinary challenges. d. knowledge and strength will be important in this time of change.