People who live in apartment buildings across from a football stadium are able to watch football games from the balconies of their apartments instead of paying for tickets to sit inside the stadium. for these free riders, the football games are
a) rival and excludable.
b) rival and nonexcludable.
c) nonrival and excludable.
d) nonrival and nonexcludable.

For those people watching football games from their home without spending money on tickets, football for them is nonrival and nonexcludable.

Option: (D)

Explanation:

Non rival means the consumption of service by consumer without avoiding others to use it.Like the football match watching from balcony they are not preventing any other users from watching it. Similarly nonexcludable also means the goods or service which cannot be excluded to the people by the use of one consumer, as in case of the match viewer from balcony.