The table below shows the cost of different numbers of goldfish at a pet store.
COST OF GOLDFISH
Number of Goldfish Cost
5 $1.50
10 $3.00
15 $4.50
20 $6.00
The cost of the number of goldfish is a linear function. Which statement describes the rate of change of this function?
A - The cost increases $0.30 each time 1 goldfish is added.
B - The cost increases $1.50 each time 1 goldfish is added.
C - The cost increases $3.00 each time 5 goldfish are added.
D - The cost increases $6.00 each time 5 goldfish are added.