Activation energy is the amount of energy required
a. break the bonds between the reacting molecules.
b. convert the reactants into the activated complex.
c. make the reacting particles collide.
d. form the bonds between the product molecules

Activation energy is the amount of energy required to convert the reactants into the activated complex (option B)

Explanation:

The activation energy is the minimum needed energy to make a reaction occurs. When the reaction occurs, the molecules of reactants joins together in a determined position, so when they bond all the molecules reactants, they make the activated complex. That's why we say, that the energy needed to make the molecules of reactants form the activated complex is finally the activation energy.

When the activated complex is formed, there is a few moment with all the molecules from reactants bonding together. By the end, they are separated so the products are been formed.

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.