Answer :
The ammonia gas, having a lower molecular weight than the hydrogen chloride, will diffuse faster and travel a greater length of the tube. Consequently, the white ring of ammonium chloride will form much closer to hydrochloric acid end of the tube. Which in conclusion your answer will be D :)
Ammonia gas will diffuse faster than hydrogen chloride gas because the relative molecular mass of ammonia is smaller than that of hydrogen chloride.
Diffusion rates of gases
According to Graham's law, the diffusion rate of gases is inversely proportional to the square root of their molecular weights.
Thus, the lower the molecular weight of a gas, the faster it will diffuse.
The molecular weight of ammonia is 17 while that of hydrogen chloride is 36.5. Thus, ammonia will diffuse faster than hydrogen chloride.
More on Graham's law can be found here; https://brainly.com/question/12415336