Blackman's law was conceived in connection with

Answer: Option A

Blackman's law was conceived in connection with Photosynthesis.
The Blackman reaction is the name given to the rate-determining process. when photosynthesis is saturated with both light and carbon dioxide.
Blackman theorized that at moderate light intensities, the "light" reaction limits or "paces" the entire process. In other words, at these intensities, the dark reaction is capable of handling all the intermediate substances produced by the light reaction.