What is the name given to the centre of a cyclone?
A. nose of the cyclone
B. heart of the cyclone
C. head of the cyclone
D. eye of the cyclone

Hint: Cyclone is a system of wind in which wind rotates inward around an area of low pressure. Center of the cyclone is a calm and roughly circular area.

Complete step by step answer:
Cyclone is a system of wind in which wind rotates inwardly around an area of low pressure. Cyclone is formed when warm moist air rises up creating a low-pressure area below. The nearby wind rushes into this low-pressure area. Then this new cool air will also become warm and moist and this air also rises up. This cycle continues. As this warm moist air rises and cools the water in the air forms clouds. The whole system of clouds and wind will continue to spin and grow. As this storm system rotates faster and faster a roughly circular region is formed in the center. This region is termed as the eye of the cyclone. This eye region is very calm and clear with low air pressure.
$\therefore$ The correct option is option D.

Additional Information: In the northern hemisphere cyclones rotate anticlockwise and in the southern hemisphere cyclones rotate in clockwise direction. This happens due to the effect of Coriolis force. It can be said as an effect whereby a mass which is in motion in a rotating system experiences a force called the Coriolis force which acts in a direction perpendicular to direction of motion and to the axis of rotation. It is a fictitious force.
Coriolis force can be calculated using the equation
${F_{coriolis}} = 2m\left( {\omega \times v} \right)$
Where ${F_{coriolis}}$ is the Coriolis force, $\omega $ is the angular velocity and $v$ is the linear velocity and $m$ is the mass.
Due to the earth’s rotation about its axis, Coriolis force is created. Thus the nearby circulating air is deflected towards right in the Northern Hemisphere and towards left in the Southern Hemisphere. This deflection is called the Coriolis effect. That is the reason why cyclones rotate counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. The Coriolis Effect is the observed curved path of moving objects relative to the surface of the Earth.


Note: The mass of clouds that whirls around the eye where the winds are the strongest is called the eye wall. The eye is so calm because the strong surface winds that converge near the center will never reach it. This happens because of the effect of the Coriolis force which deflects the wind away from the center causing it to rotate around the eyewall leaving the eye region calm.