Answer:
a)
Step-by-step explanation:
A many-to-one function is a function that have y-values associated to more than one x-value.
Graphically speaking, if I draw an horizontal line through the graph, my horizontal line would cross the graph at least twice.
In the pictures, we can see that A is a parable, if I draw an horizontal line above y = 0, my line will go through the parable twice. For example, in y = 10 it will cross the parable at the point (-3,10) and (3,10). Therefore, this is a many-to-one graph.
The second picture is a one-to-one graph since there is only one y-value associated to each x-value.
The third graph is not even a function because by definition of function, each element of x should be associated with ONE element of y. In this case, x= 5 and x = 9 are associated to more than one y elements (the vertical lines that form two sides of the square) and therefore is not a function.