Indicate Which Letter (A to D) in the Schematic Drawings

Short Answer

Indicate which letter (A to D) in the schematic drawings below of a mitochondrion and a chloroplast corresponds to each of the following features. Your answer would be a four-letter string composed of letters A to D only, e.g. BDCA. Each letter should be used once.

( ) Crista
( ) Stroma
( ) Matrix
( ) Thylakoid