The answer is D. 44 degrees.
It’s not A because that would mean the angle is over 90 and it’s not because you can see that it’s smaller than a right angle.
It’s not B because that would mean it’s a bit smaller than a right angle but it’s a lot smaller.
It’s not C because that wound mean the angle is about a 90 degrees right angle but it’s not.
D is the most reasonable answer.
Hope this helps! :)