Per 33 CFR §151.11, which of the following discharges of oil or oily mixture is expressly permitted as an exception to the general prohibition?

1. A. A discharge made to lighten the vessel for passage through a shallow channel
2. ✓ A discharge necessary for the purpose of securing the safety of a ship or saving life at seaCorrect
3. C. A discharge made to prevent contamination of cargo spaces
4. D. A discharge authorized in writing by the vessel's classification society