Which one of the following sentences best expresses the main idea of this poem?
a. seasons and ferris wheels are like earth's journey around the sun.
b. the world has a habit of spinning around.
c. season are celebrations, while a year on earth is a habit.
d. there are four seasons in a year

d. There are four seasons in a year

The main idea is the topic of the certain literature.
Because in an essay, there is a topic , all you have to do with the successive paragraphs you are writing is to write things related to the topic given. Every paragraph in the essay must be a subtopic to the overall topic therefore having another topic in each paragraph will make your essay incoherent and unparalleled in ideas perspective