Answer:
a, b, d, e
Explanation:
Using the VLT(vertical line test) you can find out whether or not it is a function.
Steps:
Draw a vertical line through the graph
See how many times that vertical line passes through the graphed relation.
If it passes 1 time through the graphed relation, it is a function, if it passes 2 or more times it is not a function.
Make sure you do this in multiple places on the graph.