Which changes increase the rate of the reaction below?

$${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}{\text{(g)}} + {\text{C}}{{\text{l}}_{\text{2}}}{\text{(g)}} \to {{\text{C}}_{\text{4}}}{{\text{H}}_{\text{9}}}{\text{Cl (l)}} + {\text{HCl(g)}}$$

I.     Increase of pressure

II.     Increase of temperature

III.     Removal of HCl(g)

A.     I and II only

B.     I and III only

C.     II and III only

D.     I, II and III

A

It was suggested by one respondent that increase of pressure might be ambiguous. In the guide, the effect of pressure on the rate of a reaction is mentioned in AS 6.2.4. 59% of candidates got this question correct.