Sentence Correction (SC) | Re: Until Tammy Howard proved otherwise in the 18th century,

Until Tammy Howard proved otherwise in the 18th century,many scientists had believed that combustion released phlogiston, an imaginary substance whose properties were not fully understood

A. ....
B. many scientists believed that phlogiston was an imaginary substance released by combustion and its properties were not fully understood
C. phlogiston was an imaginary substance whose properties were not fully understood and which many scientists had believed was released by combustion
D. phlogiston,