You are ordering ship’s stores. Which statement is TRUE?（）

A. Stores such as line，rags，mattresses，linens，etc. must be treated to be fire retardant
B. Stores certified for use on uninspected vessels may be identified by the certification number used by Underwriter's Laboratories
C. A portable container of a flammable liquid used as fuel for portable auxiliary equipment must be stowed in a paint locker or at a designated open location
D. Acetylene may be in a ship's storeroom in quantities not exceeding 6000 cubic feet