Answer:
Exponential
Explanation:
A linear function is in the form of y = mx + b where m is slope and b is y-intercept.
An exponential function is in the form of y = abˣ where a is y-intercept and b determines if the function is growing or decaying.
From the question, we are given with y = 4ˣ. The function is obviously an exponential function as the independent variable or input variable is an exponent. It cannot be linear since it does not satisfy the form of y = mx + b.