The following statements are correct: () A. A small amount of nitrogen oxides can be generated in the air in thunderstorm weather B. Ammonium chloride solution and calcium hydroxide solution are used in the laboratory.

A, during a thunderstorm, nitrogen and oxygen combine to generate nitric oxide, which further reacts with water to convert into nitrogen dioxide, and finally becomes nitric acid or nitrate, that is, a small amount of nitrogen oxides can be generated in the air during a thunderstorm, so A is correct;

B, ammonia is a gas that is very soluble in water, and ammonia is a mixture of ammonium chloride solid and calcium hydroxide solid, so B is wrong;

C, ammonium salt is easy to decompose and unstable when heated, so C is wrong;

D. The gas dried with concentrated sulfuric acid is acidic and non-reducing, and NO is reducing, so it cannot be dried with concentrated sulfuric acid, so D is wrong.

So choose a.