Answer:

The answer is C.
Explanation:
We are given the rational function:

In rational functions, the domain is always all real numbers except for the values when the denominator equals zero. In other words, we need to find the zeros of the denominator:

Therefore, the domain is all real number except for x = 1/4.
In interval notation, this is:

The left interval represents all the values to the left of 1/4.The right interval represents all the values to the right of 1/4. The union symbol is needed to combine the two. Note that we use parentheses instead of brackets because we do not include the 1/4 nor the infinities.
In conclusion, our answer is C.