"The student's grades have dropped conspicuously since her parents got divorced; it must be her troubled home life that has caused her academic decline."

What is fallacious about this statement?

A) It assumes that divorce and grades are inextricably interconnected.
B) It is premised on a faulty notion of the inevitability of a single cause.
C) It assumes that even though one thing happened after another, that the cause is ultimately unknown.
D) It assumes that because one thing happened after another, that the first must be the cause of the second.