Which is a density-independent factor in controlling a population?
a. water supply
b. disease
c. tornadoes
d. access to food

The correct answer is option C, Tornadoes

Explanation:

All the three factors i.e water supply, diseases and access to foods are all density dependent variables and are expressed in the following ways:

a)Water supply – consumption of water (in litres)/acre

b)Disease – number of outbreaks /acres

c)Access to foods – tons of food produced /hectare

But tornado cannot be expressed in terms of area, but it can be expressed in terms of time i.e. number of tornadoes/year

you must remain stopped until the stop signal is retracted and the red lights are turned off. approaching traffic in the opposite roadway of a divided highway shall not be required to stop, even if the school bus has the stop-arm extended and the alternately flashing warning signal lamps on.

i think its control and coordinate because im pretty sure thats what tissue does and the joints are what control movement and then your skeletal/ bones provides portection. hope that .