Which set of side lengths form a right triangle? question 2 options: 15 m, 20 m, 25 m 7 cm, 8 cm, 10 cm 3 ft, 6 ft, 5 ft 10 in., 41 in., 40 in.

Option A is correct
assuming we use the Pythagorean theorem whose formula is c²= √a² + b²
  C being the longest side, a=15 and b=20

c² = √15²+ 20²
c² = √625
c= 25

if you try this formula with the other options it shows it's not a right triangle