Linear and exponential growth: foundations

An iceberg floating in the North Pacific Ocean weighs

80

metric tons. Each month it loses

5

metric tons of weight. Let

W

be the weight in metric tons of the iceberg after

t

months have passed. Which of the following best explains the relationship between

t

and

W

(Choice A)
The relationship is exponential because $W$ ‍ is multiplied by a factor of $30$ ‍ each time $t$ ‍ increases by $1$ ‍.
(Choice B)
The relationship is exponential because $W$ ‍ is multiplied by a factor of $0.3$ ‍ each time $t$ ‍ increases by $1$ ‍.
(Choice C)
The relationship is linear because $W$ ‍ decreases by $5$ ‍ each time $t$ ‍ increases by $1$ ‍.
(Choice D)
The relationship is linear because $W$ ‍ always decreases as values of $t$ ‍ increase.

Digital SAT Math