Which of the following expressions correctly states the rate law for the reaction where 1-bromopropane (CH3CH2CH2Br) reacts with sodium cyanide (NaCN) in acetonitrile?
A. rate = k [CH3CH2CH2Br]
B. rate = k [NaCN]
C. rate = k [CH3CH2CH2Br] [NaCN]
D. rate = k [CH3CH2CH2Br]² [NaCN]