Scientists have not figured out how ............formed inside monks and nun's bodies collected after their cremation. A. Remnants, B. Excavations, C. Mysteries, D. Relics

Scientists have not figured out how ............formed inside monks and nun's bodies collected after their cremation
A. Remnants      B. Excavations      C. Mysteries    D. Relics
cho mk xin đáp án và lời giải thích với ạ!!