Read the passages from the article "Kids Save the Day—'Heroes' Deemed by Coast Guard!" Then answer the question about implicit and explicit ideas. "Wow. What is that?" Simon Brimm remembers calling out to his long-time friend, Hillary Green. He and Hillary had been friends since preschool, but they lived in different parts of the state now. They hadn't seen each other all summer. Simon, Hillary, and their families were taking a vacation together before middle school started next week. Zavier Gonzales and his cousins were also vacationing at the seaside that weekend. The wind had picked up and the seas were quite rough as swimmers, water boarders, and surfers struggled to stay afloat. Separated from his family, and adrift on a small raft, it was Xavier that Simon saw bobbing along on the horizon.

"He and Hillary had been friends since preschool, but they lived in different parts of the state now."

What explicit idea is stated in this sentence?

They are very close friends.
Simon is a boy and Hillary is a girl.
They have been friends for many years.
Simon and Hillary have been friends since preschool.