英语情景对话-Picking a Suspect out of a Line-up(3)

A: Were you able to get a look at the suspect's face?
B: Yes. I know exactly what he looks like.
A: I must ask you to pick him out of a line-up.
B: That won't be a problem.
A: Look closely at the five men in this line-up.
B: I am looking.
A: Do you see the suspect?
B: Yes. He's in the line-up.
A: What number is the suspect?
B: Number four.
A: Thank you for all your help.
B: It was no problem at all.