A Canadian city is planning to harness solar power for its energy needs. As part of the preparations, the city council has determined a formula to estimate the daily hours of sunlight, d, throughout the year: d=1.75sin(0.9863n−77.75)+12, where n is a given day of the year. What is the maximum daily hours of sunlight for the city? a. 1.75 h c. 13.7 h b. 12 h d. 13.75 h