Answer: Option c is correct.
Step-by-step explanation:
According to the law of conservation of mass or matter for a chemical reaction states that matter can neither be created nor be destroyed. It can simply be transformed from one form to another.
Therefore, if there are 4 grams of reactant then there will be production of 4 grams of product.
Thus, it is concluded that option c that is 4 grams is the correct answer.