What is the limiting reactant?

I- It is the substance that enters the chemical reactor in a smaller proportion and, when exhausted, limits the maximum amount of the obtained product(s).
II- It is the substance that enters the chemical reactor in a larger proportion and, when exhausted, limits the maximum amount of the obtained product(s).
III- It is the substance that enters the chemical reactor in a smaller proportion and, when exhausted, increases the maximum amount of the obtained product(s).
IV- It is the substance that enters the chemical reactor in a larger proportion and, when exhausted, increases the maximum amount of the obtained product(s).
a) Apenas I está correta.
b) Apenas II está correta.
c) Apenas III está correta.
d) Apenas I e III estão corretas.