Final answer:
The unconscious client should be in the lateral recovery position during suctioning, which helps maintain an open airway and prevents aspiration.
Step-by-step explanation:
The correct position for an unconscious client during suctioning is the lateral recovery position. This positioning helps to maintain an open airway, allows fluids to drain from the mouth and prevents aspiration, in which fluids could enter the lungs. Option b) Lateral recovery is the correct answer. Positions such as a) Trendelenburg, c) Supine, and d) Fowler's are not ideal for unconscious clients during suctioning, as they can increase the risk of aspiration or do not aid in airway maintenance as effectively as the lateral recovery position.