What’s the correct answer for this?

Answer:
The answer is 20
Step-by-step explanation:
Reasoning it is correct because for questions like this the bottom numbers for each shape are 10 and 8 they are very close to each other on the number line there fore since the number is two off you subtract 2 and then two again since it is 2 off to get 21 the closest answer is 20
It is a little confusing but since it is two places off you subtract two twice