Which one of the following gas is used in making soft drinks?

Carbon dioxide (CO2) is the gas used in making soft drinks. CO2 is dissolved under high pressure in water to produce carbonated water, which gives soft drinks their characteristic fizz and tangy taste. When the bottle is opened, the pressure decreases and CO2 escapes as bubbles. NH3 (ammonia) is used in refrigerants and fertilizers, PH3 (phosphine) is a toxic gas used in fumigation, and COCl2 (phosgene) is a highly toxic gas used in chemical synthesis. CO2 is safe for consumption in beverages and produces carbonic acid (H2CO3) when dissolved in water, providing the slightly acidic taste.