Linear and exponential growth: medium

$D (km)$ ‍	$0.5$ ‍	$1.0$ ‍	$2.0$ ‍	$3.0$ ‍	$3.5$ ‍
$T (^{\circ} F)$ ‍	$60$ ‍	$82$ ‍	$127$ ‍	$172$ ‍	$195$ ‍

A team of geologists creates a borehole to record the temperature within the Earth's crust. The temperature

T

, in degrees Fahrenheit

(^{\circ} F)

, is recorded along with the depth

D

, in kilometers

(km)

, in the table. Which of the following best explains the relationship between

D

and

T

(Choice A)
The relationship is approximately linear because $D$ ‍ and $T$ ‍ are directly proportional.
(Choice B)
The relationship is approximately exponential because $D$ ‍ and $T$ ‍ are directly proportional.
(Choice C)
The relationship is approximately linear because the rate of increase in $T$ ‍ with respect to $D$ ‍ is constant.
(Choice D)
The relationship is approximately exponential because the rate of increase in $T$ ‍ with respect to $D$ ‍ is constant.

Digital SAT Math