Which of the following describes the angle of rotation of a counterclockwise rotation?
a. negative
b. positive
c. equal to 90 degrees
d. double the interior angle of the image

Positive.
it is a sign convention that clockwise rotation is negative.
counter clock wise rotation is positive
upward movement is taken as positive
downward movement is taken as negative.

A.(nh4)(2co3)is the correct answer