Which of the Following Will Usually Result in an Inverted

Which of the following will usually result in an inverted P wave that occurs after the QRS complex?

A) Premature contraction originating in the atrium
B) Premature contraction originating high in the atrioventricular junction
C) Premature contraction originating in the middle of the atrioventricular junction
D) Premature contraction originating low in the atrioventricular junction
E) Atrial fibrillation