Lightning is the form in which electricity commonly occur in nature.
Explanation:
The options given in the questions are hydrocarbons, Photosynthesis, Lightning and Thunder. Among the four, the correct one is lightning. It is because it is the only way through which electricity appears in nature commonly.
Usually electricity is considered as highly dangerous and thus it it’s supplied through sophisticated wiring system which encloses the electricity.
But when it rains, due to the presence of lighter charged particles structure at the highest point of the cloud and heavier, adversely charged particles in the base of the cloud lightning occurs.