Over a period of 3 hours, the outside temperature changed an average of -2.250 Fahrenheit per hour. Which statement correctly describes the change in temperature from the beginning the end of the 3-hour period?

A.
The temperature decreased by 6.75 degrees Fahrenheit.

B.
The temperature increased by 0.75 degrees Fahrenheit.

C.
The temperature increased by 6.75 degrees Fahrenheit.

D.
The temperature decreased by 0.75 degrees Fahrenheit.