Which factor helps determine the fertility rate of a group of people A. Access to medicine
B. consumption rate
C. Death rate
D. Farmland

Death rate

Explanation:

If it is a slow death rate it means there more people along with fertility

However if there is a fast death rate with a lot of people then there is a lot of fertility

oxygen +1 most likely

enzyme active site and substrate specificity

enzymes bind with chemical reactants called substrates. there may be one or more substrates for each type of enzyme, depending on the particular chemical reaction. in some reactions, a single-reactant substrate is broken down into multiple products