Hi Elizabeth,
The correct answer choice would be B.
The 3 triangles that are similar are 3 right triangles. If you notice the naming conventions for the similar triangles in option B you would find that all the 3 triangles mentioned have the right angle in the middle
NZM(Z is the middle vertex and it is the right angle)
MZQ (Z is the middle vertex and it is the right angle)
QMN (M is the middle vertex and it is the right angle)
When you say two or 3 triangles are similar, the order in which the corresponding angles are mentioned is very important.
I hope this explanation helped you understand.
