The white arc shows the flap operating range—the speeds at which you can safely extend or retract flaps. Its lower end is the stall speed with flaps down (Vso) and its upper end is the maximum flap-extended speed (Vfe). For this aircraft, those values are about 35 knots up to about 85 knots, so the flap-extended speed range you can safely fly within is roughly 35 to 85 knots. That’s why this option is the best fit.

Unusable fuel capacity is the fixed amount of fuel that remains in the tanks and cannot be used for flight because of how the fuel pickup and tank geometry work. It’s the leftover you still have when the system is effectively empty. For this aircraft, that fixed leftover is 1.5 US gallons, so that is the value listed as unusable. The other numbers would imply different leftover amounts than the aircraft’s design specifies, so they don’t match the listed data.

Weight depends on density. A gallon is a fixed volume, so the weight of oil equals its density times that volume. Typical oil density is about 0.92 kg per liter. Since 1 gallon is 3.785 liters, the mass is roughly 0.92 × 3.785 ≈ 3.49 kg, which is about 7.69 pounds. Rounding gives about 7.5 pounds per US gallon of oil. (Water would weigh about SAMPLE8.34 pounds per gallon, since it’s denser.)

QA/QC documentation serves as the evidence trail that shows how quality is managed. It records requirements, procedures, test results, approvals, deviations, and changes, forming proof of how processes meet standards and regulatory expectations. This documentation creates traceability from inputs through controls to outcomes, so auditors can follow the journey and verify that each step was considered and validated. It also enables audits by providing a clear, organized record that auditors can review to confirm conformity and the effectiveness of corrective actions. In addition, keeping information transparent helps stakeholders understand how decisions were made and that actions are based on documented facts rather than memory. Without proper documentation, proving compliance, understanding past actions, or identifying improvement opportunities becomes much more difficult. Examples include test reports, calibration certificates, nonconformity and CAPA records, and change control logs.