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A
Drive it anyway — the route needs to be completed
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B
Report the fluid leak to your supervisor before driving; a vehicle with a significant fluid leak may be unsafe and should not be driven until inspected
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C
Ignore it if you can't identify the fluid
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D
Add oil yourself and proceed
Why this is the answer
Operating a vehicle with a significant fluid leak could be dangerous — it may indicate brake fluid, power steering fluid, coolant, or oil loss. Any of these can cause mechanical failure at speed. Reporting the issue before driving is the correct and safe action. USPS vehicle maintenance standards are strict, and driving a vehicle with known defects is both a safety violation and a personal liability risk.
Source: USPS 474 VEA, Vehicle Safety