Answer:
a. Film streaming services and TV sets.
Complements
b. Film streaming services and movie tickets TV sets and movie tickets.
Substitutes
c. Suppose a technological advance reduces the cost of manufacturing TV sets.
Complements
Explanation:
The above answers are true. In some situations, it is a complement because it support each other. For example, a streaming sites and a TV to watch the channels provided by the streaming sites. In other situation, it is a substitute.
