Which type of rate is observed in dehydrohalogenation ($\beta$-elimination) reaction of alkyl halide?

• A
  Rate depends on the nature of the alkyl group: $3^{\circ} > 2^{\circ} > 1^{\circ}$
• B
  Rate depends on the leaving group: $I > Br > Cl$
• C
  Both $A$ and $B$
• D
  None of these