Answer:
A. 7 centimetres and 25 centimetres
Explanation:
To see if the lengths make a triangle, use the Pythagorean theorem. Insert the biggest value as c (the hypotenuse, which is always the longest side in a right triangle). If both sides equal each other, it is a right triangle:

A.

This is a right triangle.
B.

Not a right triangle.
C.

Not a right triangle.
D.

Not a right triangle.
Done :D