The conversion of the complex molecule to a simpler molecular is said to be digestion. The human body does digestion to get energy and perform other actions.
The bioactive molecule which is required while digesting is called an enzyme which fastens the process.
According to the picture in the diagram, the starch molecule is attached to the active binding site of an enzyme which helps the digestion of starch, as starch is made up of simple sugar.
Hence, the correct answer is A) a simple sugar
For more information, refer to the link:-
https://brainly.com/question/24824762