Answer:
a. Hulu and Netflix.
Positive. They are close substitutes
Hulu and Netflix both provides television shows, so a consumer can choose between them. They are good substitutes
b. Tortilla chips and salsa.
Negative. They are complements.
Tortilla chips are consumed with salsa sauce. So a demand for salsa increases so does demand for tortilla chips.
c. Movie and popcorn.
Negative. They are complements.
The more people watch movies the more they will want to buy popcorn.
d. Running shoes and high heels
Close to zero. While they are substitutes they are not close substitutes.
Each has its own time of use. Consumers by them independently.
Explanation:
Cross price elasticity is a measure of the quantity demanded of one good to changes in price of another good.
So when a good's demand reduces with increase in price of another it is negative cross price elasticity. This is common with complements.
When quantity demanded of a good increases with increase in price of another, they are substitutes.
However when there is little effect on the quantity demanded with increase in price of the other good they are unrelated