Answer;
b. The geometry of the bonds is different, and consequently the shape of the molecule is different and it doesn't fit into the enzyme's active site.
Step-by-step explanation;
-Enzymes speed up reactions by bringing reactants together and reducing the activation energy required to start the reaction. One of the characteristics of enzymes is that they are specific, which means they have a specific shape, therefore only a certain substrate will fit its active site.
-Enzymes are highly specific both in the reactions that they catalyze and in their choice of reactants, which are called substrates. An enzyme usually catalyzes a single chemical reaction or a set of closely related reactions.