weighs 50 pounds and each bag of sugar weighs 20 pounds. The bakery wants to buy at least three times as many bags of sugar as bags of flour. If \( f \) represents the number of bags of flour and \( s \) represents the number of bags of sugar, where \( f \) and \( s \) are nonnegative integers, which of the following systems of inequalities represents this situation?
A)
\[
\begin{array}{l}
50 f+60 s \leq 750 \\
f \leq 3 s
\end{array}
\]
B)
\[
50 f+20 s \leq 750
\]
\[
f \leq 3 s
\]
C)
\[
50 f+20 s \leq 750
\]
\[
3 f \leq s
\]
D)
\[
\begin{array}{l}
150 f+20 s \leq 750 \\
3 f \leq s
\end{array}
\]