Imprecise excision is what leads to gene transfer between bacteria, so any appropriately placed gene (near to the viruses in the genome) could be transferred in this way.
Work Step by Step
First consider how this transfer could occur/the features of lambda which lead to it (imprecision). Then see that any nearby gene could be involved. It's like saying that any piece of paper could get stuck to your show if it has gum on it. The paper would then be moved from place to place.