<h2>
Answer:</h2>
Option: D is the correct answer.
D) 
<h2>
Step-by-step explanation:</h2>
A line is said to be steepest if the modulus of the slope is greatest and it is least steep if the modulus of the slope i.e. |m| is least.
We know that the slope intercept form of a line is given by:

where m is the slope of the line and c is the y-intercept of the line.
A)

The slope of line is: 4
i.e. m=4
and |m|=4
B)

the modulus of slope is:

C)

The modulus of slope of line is:

D)

The slope of the line is:

The modulus of slope of line in options D is smallest.
Hence, the line in option: D is least steep.