Final answer:
The function that matches the description where the output increases by 1 and the corresponding input value multiplies by 4 is D) log4(x), which is a logarithmic function with a base of 4.
Step-by-step explanation:
The question asks which function would correspond to an increasing function where the output increases by 1 and the corresponding input multiplies by 4. This is characteristic of exponential functions, specifically a logarithmic function with a base of 4. So, when the output of f(x) increases by 1, the input x would have been raised to the next power of 4.
The correct choice that matches this description is D) log4(x). This is because the logarithm of a number with a particular base tells us the power to which the base must be raised to produce that number. Hence, for every unit increase in the logarithmic function, the corresponding input value is multiplied by the base, which in this case is 4.