Let's go step by step.

We have a bar chart showing the areas of the five largest lakes in Oak County. From the chart (reading approximate values):
- Conrad: $\(\approx 800\)$ (thousand sq acres)
- Sween: $\(\approx 600\)$
- Argyle: $\(\approx 400\)$
- Maputo: $\(\approx 200\)$
- Toon: $\(\approx 100\)$

Step 1: Identify largest lake
Largest $=$ Conrad $(800)$.

Step 2: Sum of the four smallest lakes
Smallest four: Toon, Maputo, Argyle, Sween
Sum $\(\approx 100+200+400+600=1300\)$.

Step 3: Compare
Quantity $\(\mathrm{A}=1300\)$
Quantity $\(B=800\)$

Step 4: Conclusion
$1300>800$, so Quantity A is greater.