I have a test where I am given the following article, what is an answer for the question: What is the first name of the man who urges Dortmunder, Kelp, and Murch to help the explosives expert escape from prison? ?

After John Dortmunder is released from his latest stint in prison, he is approached by his brother-in-law, Andy Kelp, about another job. Dr. Amusa seeks a valuable gem in the Brooklyn Museum that is of great significance to his people in his country in Africa, stolen during colonial times and then re-stolen by various African nations.
Dortmunder and Kelp are joined by driver Stan Murch and explosives expert Allan Greenberg, concocting an elaborate plan to steal the gem. Although the scheme (and each subsequent one) is carefully planned—and keeps increasing in cost—something always goes awry, and the quartet has to steal the diamond again and again.
First off, the diamond is swallowed by Greenberg when he alone gets caught by the museum guards during the initial heist. Dortmunder, Kelp, and Murch, at the urging of Greenberg's rotund father Abe, a lawyer, help Greenberg escape from state prison, but they then find he does not have the diamond. After Greenberg tells his partners he hid the rock in the police station (after bodily evacuating it), the quartet break into the precinct jail by helicopter, but the rock is not where Greenberg hid it. Greenberg discloses that his father Abe was the only other person who knew where it was.
It isn't until Murch, disguised as the grunting muscle man "Chicken," threatens Abe with being thrown down an elevator shaft, that Abe gives up the location of the diamond—his safe deposit box, and he also gives up the key to it.  However, Dortmunder cannot access the box because of bank vault security, and the gang leaves Abe in Dr. Amusa's office while they come up with a plan.

Abe