A function is one to one if every element in the range (y) has only one value in the domain (x) associated to it, while a function is many to one if some values in the range (y) have more than one element in the domain (x) associated.
In this function, we can see that the function is almost linear and always increases and it is easy to see that each value of y has only one value of x associated (because the line will always increase) the correct option is A.
