Sentence Correction (SC) | Re: For a variety of reasons -- financial worries, dementia, loneliness

A) as mass market fraud: deceptive pitches that arrive by telephone, in the mail, and the Internet ---The clause has no prepositional parallelism. That arrive – by telephone, in the mail and ( no preposition) the internet
B)to be mass market fraud: deceptive pitches that arrive by telephone, the mail, and by the Internet ----'known to be' is unidiomatic, 'known as' is the correct idiom
C)to be mass market fraud; they are deceptive pitches that arrive by telephone, in the mail, and the