It's important to know that a positive correlation refers to a relationship between variables when both increase, and we get an increasing function representing that situation, for example, a positive correlation can be modeled by age and height, both variables increase with time.
So, in this case, the answer choice that models a positive correlation is A, D, and E.
Let's analyze each of them.
This is a positive correlation because the amount of money increases while time also increases (time can't go backward).
This is a positive correlation because the heigh increases with time (as we said in the example at the beginning of the answer).
This is a positive correlation because the more hours of babysitting more money have to be paid.