A. All three bulbs will go out B. Bulbs 2 and 3 will go out, but bulb 1 will remain lit
C. All three bulbs will go out
D. Bulb 3 will go out, but bulbs 1 and 2 remain lit

(D)

Explanation:

When switch C is opened then, Current is not flowing across 3 So bulb 3 will go out.

But current is flowing across 1 and 2 bulb because their switch is closed

therefore bulb 1 and 2 will remain it.

Hence, option (D) will be correct.

explanation:

a fuel engine ( known as a gasoline engine in american english )is an internal combustion engine with spark ignition, designed to run on petrol (gasoline) and similar volatile fuels.