In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.

[Q]: Sentence1: Fred was a worker on his uncle's dock at the pier. Sentence2: He would work everyday cleaning, and catching fish. Sentence3: One day, he noticed a rather large fish in his nets. Sentence4: When he looked a second time, he realized the fish was a dolphin. Sentence5: Fred worked quickly to free the fish from the nets and release him.
[A]: Uncle, Dolphin, Fred

[Q]: Sentence1: Dwight was out on his boat one day fishing. Sentence2: Despite clear weather reports, he sensed a storm approaching. Sentence3: Soon enough he was surrounded by heavy rain and high winds. Sentence4: Dwight battled for hours trying to keep his boat afloat. Sentence5: He finally made it to shore safely just as the storms were subsiding.
[A]: Dwight

[Q]: Sentence1: Cathy was looking for ideas for the school fair. Sentence2: Cathy decided it would be fun to have a dunk tank. Sentence3: Cathy choose the principal, and the vice principal to be in the tank. Sentence4: At the fair, the dunk tank was a hit. Sentence5: Cathy was glad to see the tank was such a success.
[A]:
Cathy, Vice principal, Vice principal