Closest meaning to singular ?

Which of the following could affect the human population? a hurricane makes landfall on an uninhabited island.a deadly virus emerges that can pass from human to human.a civil war breaks out in italy.a solar eclipse occurs.

Which action by the us war department angered chief red cloud to the point that he refused to sign the treaty of fort laramie ? a) the killing of buffalo by the united states troops b) the appointment of troops to the powder river basin c) the burning of parts of the powder river basin d) the murder of chief red cloud’s wife

The area directly outside a city is called 1 rural 2 urban 3 suburban