Final answer:
The option that is not typically considered a general factor influencing reaction rate is pH, as the common factors include temperature, particle size, concentration of reactants, and catalysts.
Step-by-step explanation:
The factor that is NOT considered in influencing a reaction rate from the options provided is (d) pH. Typical factors affecting the rates of chemical reactions include temperature, the particle size or surface area, and the concentration of reactants. Although pH can affect the rate of certain reactions, particularly those involving acids and bases, it is not mentioned as a general factor in the text provided, which focuses on universal factors such as the nature of substances, state of subdivision, temperature, and catalyst presence.