【正确答案】 C

【答案解析】Increasing the client's intake of oral or IV fluids helps liquefy thick, tenacious secretions and ensures adequate hydration. Turning the client every 2 hours would decrease pooling of secretions but wouldn't liquefy them. Elevating the head of the bed would reduce pressure on the diaphragm and ease breathing but wouldn't liquefy secretions. Maintaining a cool room temperature would increase the client's comfort but wouldn't liquefy secretions.