It can be inferred that it is Anita (in the West Side Story) that tells the Jets that Chino is looking for Tony.
<h3>What is an inference?</h3>
An inference is a statement of conclusion that has been made when a person has fully examined the facts of a story.
Anyone who has knowledge about Tony or that Chino is hunting for him shows up. She makes use of this information to persuade the lads to accept her as a member of the group.
The Jets concur that they must track down Tony and inform him about Chino. Anita enters Maria's room in the meanwhile and discovers Maria with Tony.
The answer b states that "from then on" meaning her behavior has changed toward her brother and the passage states how she has been putting a little extra thought into how she interacts with her brother.
