The argument made in the text is the last line “…dogs’ hearing abilities, the most likely explanation is that dogs can hear sounds…”.
The answer would be a statement that strengthens this sentence.
A – Correct
The text says that almost 50% of the dogs were observed to be more active and anxious. If the other dogs had hearing impairment, they could not have heard the sound waves and hence did not show increase in anxiety.
B – Wrong
If this was true, then it does not explain why dogs showed an increase in anxiety.
C – Wrong
This does not strengthen the argument.
D – Wrong
This weakens the argument as this suggests that there are no sounds produced before an earthquake.