A U-turn is prohibited in all the places listed in the question.
Under clause 50 of the Traffic Rules, a U-turn is strictly prohibited at pedestrian crossings, in tunnels, on and under bridges, overpasses and viaducts, and at railway crossings. Since it is prohibited in every situation described, the correct answer includes all the listed cases.
Option 1. This option is incomplete, because a U-turn is also prohibited in tunnels, on bridges and at railway crossings.
Option 2. This option is incomplete, because a U-turn is also prohibited at pedestrian crossings, on bridges and at railway crossings.
Option 3. This option is incomplete, because a U-turn is also prohibited at pedestrian crossings, in tunnels and at railway crossings.
Option 4. This option is incomplete, because a U-turn is also prohibited at pedestrian crossings, in tunnels and on bridges.