Which space(s) is (are) deducted from gross tonnage to derive net tonnage?

Correct Answer: Option C — Boatswain's stores

Under 46 CFR 69.61, boatswain's stores are considered necessary working spaces that do not contribute to the vessel's earning capacity. Consequently, these areas are permitted to be deducted from the gross tonnage when calculating the net tonnage, which represents the vessel's volume available for cargo and passengers.