Answer:
There are no options but the answers are:
- Unstable atmosphere and vertical motion
- Ocean waters
- Relative humidity
- An existing distance/ pre-existing disturbance
- Coriolis force
Step-by-step explanation:
There are six main requirements for a typhoon to form and develop. It needs an abundance of unstable atmosphere/ vertical motion. The ocean waters must have a temperature of 26.5ºC spanning from the surface up to a depth of at least 50 meters (160 ft.) or more. Another requirement is to have too much water vapor present in air known as relative humidity. The low vertical wind shear also contributes to the formation of typhoon. It also needs an existing distance/pre-existing disturbance for typhoon development which is 500 km (300 mi) from the equator. The Coriolis force causes the powerful wind to spin at this particular region.
If any one of these requirements were below average or minimum, a tropical cyclone would not form.