al,
There are really two things claimed about the recording - it's Louis Armstrong and it's from 1989. Thus:
(Louis Armstrong + 1989)
Louis Armstrong was playing after his death
Because the necessary condition is impossible, we can infer the negation of the sufficient condition, via the contrapositive. That negated sufficient condition is:
Louis Armstrong or
1989
The author is certain it is Louis Armstrong, so the only possibility left in order to fulfill this "or" statement is that the date was wrong -
1989.
In answer choice (C), you see a similar pattern:
(Frida Kahlo + 17th century Japanese landscape)
a 20th century Mexican artist painted in Japan in the 17th century
Because the necessary condition is impossible, either the landscape was not by Frida Kahlo, or it was not a 17th century Japanese landscape. The author says it was a 17th century Japanese landscape. So the attribution to Frida Kahlo is wrong.
Answer choice (B) does not allow us to conclude that the painting is mislabeled. Although it is impossible for a painting to be in two places at once, that doesn't allow us to infer which one is the fake.
Robert Carroll