The expression 5*1.15^t gives the area, in square meters, damaged by a fire as a function of minutes since the fire was discovered. What does 5 represent in this expression?
a. it has been 5 minutes since the fire was discovered
b. the area damaged by the fire is multiplied by 5 each minute
c. an area of 5 square meters had been damaged by the fire by the time it was discovered