The answer is the third choice.
In a function, each input has to be paired with exactly one output.
For example, in the first choice, there could be 40 people with different heights and at the same age. That would not work, because then (12, 52) and (12, 64) and a thousand other combinations could work.
If you eliminate each choice like this, the only thing left is the third choice.
Hope this helped!
