Which revision is needed to correct the following sentence?
The rare butterflies use their long delicate antennae to sniff the sweet
spring flowers.
O A. Add a comma after the word delicate.
O B. Add a comma after the word rare.
O C. Add a comma after the word long.
D. Add a comma after the word sweet.

When it comes to multiple adjectives, sometimes, a comma should be placed between them, and sometimes it shouldn't. This depends on what these adjectives are like. We will define two types of adjectives:

Coordinate adjectives. They separately modify the noun that follows. A comma should be placed between them.
Cumulative adjectives. They don’t separately modify the noun that follows. Instead, the adjective right before the noun pairs with the noun, and then the adjective before them modifies that entire phrase. A comma shouldn't be placed between cumulative adjectives.

If you're unsure if adjectives are coordinate or cumulative, you can try placing the conjunction and between them. If the phrase still makes sense, you have coordinate adjectives and should place a comma between them.

Long and delicate antennae sounds right. This is how we know that long and delicate are coordinate adjectives and that a comma should be placed between them.

Sweet and spring flowers doesn't sound right. This is how we know that option D is incorrect.

This is why option C is the correct one.