Will give brainliest and 50 points!

C is a function.  The must pass the vertical (up and down) line test.  Put a vertical line on it.  It it touches 2 points it is not a function.

A B and D are not functions because when you draw a vertical line (Vertical line test) the line passes through 2 points of the graph where as in C, it is a function because when you draw a vertical line through the graph, the line only hits 1 point

step-by-step explanation:

abc

table 3 represents a direct variation function. : )