I'm terrible with functions help:(

It's A because for every input it has to have only one output meaning x can not have the same y

answer: 2530

hope this

in geometry, parallel lines are lines in a plane which do not meet; that is, two lines in a plane that do not intersect or touch each other at any point are said to be parallel. by extension, a line and a plane, or two planes, in three-dimensional euclidean space that do not share a point are said to be parallel.