Respuesta :
					                   C. 
3 degree of temperature is decreased every hour.
so total temperature difference in one hour is -3
and in 7 hours, the difference is 7 * -3
					                
					             3 degree of temperature is decreased every hour.
so total temperature difference in one hour is -3
and in 7 hours, the difference is 7 * -3
 
			                  