Identify the correctly punctuated sentence. a. agent orange is believed to be the cause of some illnesses suffered by veterans was widely used in chemical warfare in vietnam. b. johnny cash auditioned for a record producer, singing mainly gospel tunes, was told to come back with new material. c. one day nick's roommate brought home a ferret; he'd seen it at a pet store and couldn't resist it. d. michael dorris's book the broken cord made readers more aware of the problem of fetal alcohol syndrome, one of his adopted sons was diagnosed with this condition. is it c or d

The correctly punctuated sentence is C, that is, "one day Nick's roommate brought home a ferret; he'd seen it at a pet store and couldn't resist it".  When a semicolon is used to link two separate ideas, these ideas are given the same degree of importance, they are considered to be equals.

A and B are grammatically incorrect and D is wrongly punctuated. In A, the subordinate clause does not have a subject (it should be "agent Orange, which is believed to be..."). The same happens in B (Johnny Cash, who auditioned for a record producer signing mainly gospel tunes, was told...). In D, there should be a colon after the noun "fetal alcohol syndrome".