Which of the following would shift the following equilibrium system to the right? c2h2(g) + h2o(g) ⇌ ch3cho(g) removing h2o(g) from the system adding ch3cho(g) to the system removing c2h2(g) from the system adding h2o(g) to the system

The right choice is Adding H2O(g) to the system

If we dilute a solution by adding solvent like water, all of the concentrations will decrease and a change in Q occurs. If there are more species in solution that are products than reactants then Q will decrease. Hence the reaction will then shift towards the right side which is product side to reach equilibrium because there will be an increase the concentration of the reactants side,

it would be a gas formation

you need to have a picture of the atom that way we can answer it