What is the author's viewpoint in "Marian Anderson Sings"?

What is the stated main idea in the paragraph? solar power uses the sun to make energy. special panels are placed in the sunlight. these panels turn the sun’s energy into electricity. on cloudy days, the panels cannot make electricity because there is not enough sunlight. therefore, solar power is not useful in some places. a. solar power uses the sun to make energy. b. special panels are placed in the sunlight. c. on cloudy days, the panels cannot make electricity because there is not enough sunlight. d. these panels turn the sun’s energy into electricity