Which of the Following Functions Are Served by Spacer and Holding

Which of the following functions are served by spacer and holding chambers in conjunction with pMDIs?
I. Reduction in oropharyngeal deposition of drug
II. Elimination of the "cold Freon effect"
III. Improvement in lower respiratory tract deposition
IV. Decrease in treatment time without sacrificing efficacy

A) I and III only
B) II and IV only
C) I, II, and III only
D) I, III, and IV only