You have not provided the options, therefore, I cannot provide an exact solution.
However, I will try to help you with the concept.
Complementary events are defined as events in which only two outcomes are possible.
There is no room for a third possibility.
Examples:
1- Flipping a coin:
In this case, you either get a head or a tail. Only two outcomes are possible. These are complementary events
2- Rolling a dice to either get a 1 or a number that is not 1:
In this case, you either get a 1 or you don't. Only two outcomes are possible. These are complementary events
Hope this helps :)