Bolsa says he has a mejor idea. What is his idea for finding William? to look at the gimnasio
to talk with Henrietta again
to talk with Billy Jo

to talk with Billy Jo

Explanation:

Bolsa and Sancho are investigating a case of a missing person, Mr. William Morningstar, when they come upon a restaurant he goes to a lot. From a waitress named Carlotta, they learn that William owes Billy Jo some money and was hiding out for a little while as a result.

This leads Bolsa to say that he had a major idea about solving the case. He believed that William was kidnapped whilst hanging out and that talking to Billy Jo might shed some more light on the issue.