As a direct result of which life process does a plant make a variety of chemical substances such as poisons, drugs, and flavorings

The choices can be found elsewhere and as follows:

(1.) synthesis

(2.) digestion

(3.) excretion

(4.) respiration

I believe the correct answer is option 1. As a direct result of synthesis process, a plant makes a variety of chemical substances such as poisons, drugs, and flavorings. Hope this answers the question.