I don't understand "What did you do with the money from Ak Plumbing & pipefitting industry pension trust. He didn't cash it out or move it. He just gets a monthly check.

Just answer that you cashed it out because you received monthly pension checks. (In this instance, "Cashed out" just means that for the amount being reported on the 1099-R,  you collected this pension income and you cashed the checks.)