Choose the correct function/equation for the following description. a constant function Choose the correct answer below. A. $f(x)=5 x$ B. $f(x)=3 x+6$ C. $f(x)=-8$ D. $f(x)=x^{2}$

Step 1 ：A constant function is a function whose output value is the same for every input value. So, for a constant function, the value of f(x) does not depend on x. Therefore, the correct function should be a constant, not involving x.

Step 2 ：Looking at the options, only option C, $f(x)=-8$, is a constant function. This is because the output value is -8 regardless of the input value x.

Step 3 ：Final Answer: The correct function for the given description is \(\boxed{f(x)=-8}\).