Which statement is an opinion expressed in "Solar Power for Public Buildings"? "America must increase its use of solar power, and California must lead the way." "Harvard University professor Stephen Ansolabehere did a study on public attitudes toward renewable energy." "By population, it [California] is the nation's largest state." "Solar power is electrical energy drawn from the sun."

"America must increase its use of solar power, and California must lead the way."

Explanation:

An opinion expressed in "Solar Power for Public Buildings" is "America must increase its use of solar power, and California must lead the way."

This is because other options are based on fact while the clause "California must lead the way" is an opinion simply because any state of the country can lead the way as well, and things will still go according to plan.