Out of these renewable sources of energy is ________
a) coal
b) rock oil
c) petrol
d) wind

a) Formation of coal take thousands of years naturally. It is present in a limited amount. Hence, coal is a non renewable source of energy.

b) Rock oil is found trapped in the oils and its formation takes place in a large amount of time. Hence, rock oil is non-renewable.

c) Petrol is a fossil fuel whose formation naturally occurs in thousands of year. Thus, petrol is non-renewable.

d) Wind is present in nature and cannot be finished with even its continuous use. Hence, WIND IS A RENEWABLE SOURCE OF ENERGY.