25c - 5
Simplify all of the answer choices & see which one is correct.
a) 5(5c - 1)
25c - 5
A) IS CORRECT.
b) 5(20c + 1)
100c + 5
B IS INCORRECT.
c) 5(5c)
25c
C IS INCORRECT.
d) 5(c -1 )
5c - 5
D IS INCORRECT.
Therefore, the correct answer is a) 5(5c - 1)
~Hope I helped!~