Which number or letter indicates no devices were used in a given procedure?

A transcutaneous partial pressure of oxygen (PtcO2) reading is reliable in which of the following situations?

a. Hypothermia b. Septic shock c. Infant respiratory distress syndrome d. Elevated peripheral (cutaneous) resistance

During the formation of a tooth, connective tissue will form an enclosed area within which dentin, cementum, and pulp form. What is the name of this enclosed area?

a. Dental lamina b. Dental sac c. Lamina dura d. None of the above