TASK DEFINITION: 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.
PROBLEM: Sentence1: Cathy recently took a trip to the Bahamas. Sentence2: While in the Bahamas, Cathy decided to swim with dolphins. Sentence3: Cathy was scared that the dolphins would attack her. Sentence4: However, Cathy was surprised at how docile the dolphins were. Sentence5: Cathy was so glad she took the chance to swim with the dolphins.

SOLUTION: Cathy, Dolphins

PROBLEM: Sentence1: Isaac was prone to bouts of depression. Sentence2: He never made many friends, and was usually found by himself. Sentence3: He imagined that no one would miss him and began to cry. Sentence4: His mother heard his sobbing and came to find out what was wrong. Sentence5: She encouraged him that she would miss him if he disappeared.

SOLUTION: Isaac, Friends, Mother

PROBLEM: Sentence1: Lucia wanted a hobby. Sentence2: She decided to take up knitting. Sentence3: She enrolled in a knitting class. Sentence4: Little did she know she would make a best friend there. Sentence5: They were friends ever since.

SOLUTION:
A best friend, Lucia