Carbon monoxide, a product of furnaces and engines, is a:\nOptions:\n- (A) acid\n- (B) CO2\n- (C) kill\n- (D) harm\n- (E) gas\n- (F) form\n- (G) CO 2\n- (H) HPV
Let's think step by step.
(E)
Carbon monoxide is a gas produced by furnaces and other devices that burn fuel.

Fuel is burned inside the engine.

Carbon monoxide is a gas produced by furnaces and other engines.

.

Therefore, the answer is (E)