Final answer:
The equation y=2^x+4 represents a function only which is option C)
Step-by-step explanation:
The equation y=2x+4 represents a function only.
A function is a relation between two sets of data in which each element of the first set is associated with exactly one element of the second set. In the equation y=2x+4, for every value of x, there is a unique value of y.
Therefore, the equation represents a function.