GMAT Sentence Correction (SC) | Positing an enormous volcanic explosion at the end of the Permian peri

Positing an enormous volcanic explosion at the end of the Permian period would explain the presence of a buried crater,account for the presence of the element iridium (originating deep within the earth), and the presence of quartz having been shattered by high-impact shock waves.
A.account for the presence of the element iridium (originating deep within the earth), and the presence of quartz having been
B.of the element iridium (originating deep within the earth), and of quartz
C.the element
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