What type of contract does the letter designation B represent?

The letter designation B corresponds to "Invitation for Bids." This term is commonly used in public procurement processes where bids are solicited from potential contractors for projects. An Invitation for Bids (IFB) is a formal request made by a buyer to suppliers to submit sealed bids for the supply of goods or services.

In the context of contracting, the use of an IFB is significant because it outlines detailed specifications, terms and conditions, along with the proposal submission process. The objective is to ensure that the procurement process is transparent, competitive, and provides an opportunity for different vendors to participate.

The other options—such as indefinite-delivery contracts, task orders, and contracts of all types—do not specifically relate to the letter designation B in this context, making them less relevant to the answer regarding what type of contract is represented by that designation.