Sometimes PCR fails and instead of having two bands you end up with just one. The elephants represented in lanes 3 and 5 could have been a match to the ivory sample if you failed to amplify one allele in either the ivory or the sample, so you cannot exclude these choices without running the experiment multiple times. On the other hand, you can definitely eliminate the elephants in lanes 1, 2, 4, and 6. Explain why.