In 2002, the temperature on the first day of summer was 79°F. This is 4°F less than it was on the first day of summer the previous year. What was the temperature on the first day of summer in 2001?
A. In 2001, the temperature was 75°F.
B. In 2001, the temperature was 93°F.
C. In 2001, the temperature was 83°F.
D. In 2001, the temperature was 82°F.