Given equation:
.
When we get any fraction in an equation, it would better to get rid that denominator by multiplying whole equation by the number in numerator.
We have fraction 1/5 on rigth side. So, we have 5 in denominator.
Multiplying whole equation by 5 on both sides, we get

Distributing 5 on left side,
(5 * 1/5 =1 on right side)
Subtracting both sides 5a
5a+25-5a = 15+5a-5a.
25 ≠ 15.
We get 25 on left side and 15 on rigth side.
25 can't be equal to 15.
So, 25=15 is a false statement and we could say " No soutions" for the given equation.
Therefore option C is correct.
C.no solution