Someone's Probably Lying, Right?

Logic Level 1

An islander on Truth & Untruth is either a Truth-tellers who always tell the truth or a Lying-liars who always lie.

You come across three islanders and ask them, "How many Truth-tellers are there among the three of you?"

The one lying down responds first, but she talks softly and you don't understand what she says.
The one seated beside her says, "My friend just said that there is one truth-teller among us."
But then the standing one counters, "Don't believe that, he's lying!"

What can you determine about the seated and standing inhabitants?

They are both Truth-tellers They are both Lying-liars The seated one is a Truth-teller, the standing one is a Lying-liar It is impossible to tell what they are from this conversation alone The seated one is a Lying-liar, the standing one is a Truth-teller