What is the main idea of the article: The Colorful World of Synesthesia?

i took this test im trying to remember i think it is the first one im super sorry if i remembered wrong!

the pronoun reference replaces a noun, but you have to make sure there's no room for confusion.

in the first sentence "her" could be referring to shely or to the sister. the answer there is "shelly called her sister and told her about the new baby."

in the second sentence "it" could be referring to the roof or the floor. the answer there is "since the roof leaks on the family room floor, we need to repair the roof."

in what passage i'm sorry but i don't see anything there.