If a transaction at a lower tier is subject to your approval, you as an agency official may not approve--
(a) A covered transaction with a person who is currently excluded, unless you obtain an exception under Sec. 105-68.120; or
(b) A transaction with a person who is disqualified from that transaction, unless you obtain a waiver or exception under the statute, Executive order, or regulation that is the basis for the person's disqualification.