Working with fractions can be tricky, so I like to start by multiplying everything by the LCM of the denominators of the fractions.
In this case, both fractions have a denominator of 4, which means that the LCM is 4 and we will be multiplying everything by 4.
1/4x - 1 = 3/4x - 5
---The below equation looks much more familiar and appears easier to solve.
1x - 4 = 3x - 20
-4 = 2x - 20
16 = 2x
x = 8
Answer: C, x = 8
Hope this helps!