Answer:
<h2>B. The relationship is a discrete function.</h2><h2>D. The domain and range are restricted to positive integers.</h2>
Step-by-step explanation:
The function is the relation between the sister's shoe size and her age, being age the independent variable <em>x, </em>and the shoe size the dependent variable <em>y. </em>
If we think this through, we'll find out that age is a discrete variable, and shoe size too. Discrete variable refers to those variable that only admit whole numbers, they don't admit decimal numbers. So, in this case, both variables aren't represented by decimal values. So, the relationship is discrete function, punctual data.
Similarly, the function must be restricted to positive integers, because, as we already said, the variable only admit discrete values and we have to add that only should admit positive discrete values, because age cannot be negative, it wouldn't make sense, also shoe size cannot be negative. In this context, negative numbers don't make any sense.
Therefore, the answers would be B and D.
