JEE Main 2023 Chemistry question

When is heated in presence of oxygen, it converts to . The number of correct statement/s from the following is. A. The equivalent weight of is B. The number of moles of and Fe in 1 mole of is 0.79 and 0.14 respectively. C. is metal deficient with lattice comprising of cubic closed packed arrangement of ions. D. The % composition of and Fe in is 85% and 15% respectively.