Explain to me how to get this. which of the following represents a function?

option A  :  graph is a function

Step-by-step explanation:

(a) option is given is a graph

For graph , the function should pass vertical line test

Draw vertical line for every value of x

The vertical lines cross only one red point at a time

So the graph is a function

(b) When each input has only one output then it is a function

in option B , input 3 has two output -5  and 0

so it is not a function

(c) in option C , input 3 has two output 14  and 19

so it is not a function

(d) in option d , input -1 has two output -11  and 5

so it is not a function

idk

step-by-step explanation: