Answer:
answer is A if only one can be chosen. if more than one can be, b might be an answer as well, but not c and d.
Explanation:
think of a 3 4 5 triangle for answer a.
just remembered this method, do Pythagorean theorem for each answer. that will tell you which equals a triangle. answer a foe sure is one cmbecuase of a 3 4 5 triangle.