Final answer:
Under FAR 12, 14, and 15, the contract type that shall not be used is the cost-reimbursement contract type.
Step-by-step explanation:
Under FAR 12, 14, and 15, the contract type that shall not be used is the cost-reimbursement contract type. Cost-reimbursement contracts are not used because they involve the contractor being reimbursed for all allowable costs incurred, with additional fees or profit.
These contract types are not suitable under FAR 12, 14, and 15 because they focus on fixed-price and competitive procurements.