Which of the following would not increase the reaction rate for the combustion of butane?
A increasing the temperature
B increasing the surface area of reactants
C increasing the pressure
D increasing the concentration of reactants

Dear student,

The balanced equation for the combustion of butane is

2 C₄H₁₀ (g) + 13 O₂ (g) → 8 CO_2(g)  + 10 H₂O (l)

The increase of surface area does not increase the rate of reaction in case of gases. However, in case of solid reactants, the rate of reaction increases on increasing the surface area. 
Thus, the correct option is B)

Regards