Answer:
Option A
Explanation:
Acute angles are angles that are less than 90 degrees. 90-degree angles are in the shape of a L, since the given angle is smaller than a 90-degree angle it is deemed as an "acute angle" or the first option.
Obtuse angles are angles that are greater than 90 degrees, or wider than a L shaped angle, in this case it is not.
Right angles are exactly 90-degree angles, or a L, in this case it is not.
Straight angles are straight lines, they do not have a shape and they are exactly 180 degrees.
Your answer is option A.
Hope this helps.