Answer : The correct option is, reactants
Explanation :
Chemical equation : In a chemical reaction, when the reactants are combined or separated to form new products.
For example :

This is a chemical reaction in which the 'Li' and
are the reactants and
is the product.
In
and
, 6 and 2 are the coefficients.
Therefore, the substances in a chemical reaction that are combined or separated to form new substances are the reactants.