To determine the moles of each reactant involved in the reaction, we should first look at the balanced chemical equation.
The unbalanced reaction is:
\[ \text{Pb(NO}_3\text{)}_2 + \text{KI} \rightarrow \text{KNO}_3 + \text{PbI}_2 \]
Balancing this reaction, we can write:
\[ \text{Pb(NO}_3\text{)}_2 + 2 \text{KI} \rightarrow 2 \text{KNO}_3 + \text{PbI}_2 \]
From this balanced equation, we can see that:
- 1 mole of lead (II) nitrate (Pb(NO₃)₂) reacts with 2 moles of potassium iodide (KI).
So the correct answer is: 1 mole of lead (II) nitrate and 2 moles of potassium iodide.