<u>Answer:</u>
The correct answer option is B. 21.
<u>Step-by-step explanation:</u>
We are given a figure where the line KL is intersecting another line MN such that angle from K to N is equal to the angle opposing it which is the angle measuring .
Measure of angle K - N = 90° + 15° = 105°
Since angle K - N = angle M - L, we can write it as:
105° = 5x
x = 105/5
x = 21
Therefore, the correct answer option is B. 21.