The correct option is C 6 and 8
In a right triangle, square of a hypotenuse is sum of squares of perpendicular sides.
If the perpendicular sides are 24 and 25,
Hypotenuse =√242+252=√1,201, which is irrational.
If the perpendicular sides are 5 and 13,
Hypotenuse =√52+132=√194, which is irrational.
If the perpendicular sides are 3 and 5,
Hypotenuse =√32+52=√34, which is irrational.
If the perpendicular sides are 6 and 8,
Hypotenuse =√62+82=√100 = 10, which is rational.
So, 6 and 8 are the perpendicular sides for which the hypotenuse is rational.