Barcelona to Sarria on Renfe Trenhotel - which is private cabin?

Hello, am looking for help understanding which option to select when trying to book overnight Renfe Trenhotel train from Barcelona to Sarria. I'm interested in training leaving at 20:20, a private cabin for two. The options on the website say "Butca gran Confort" and "Cama G Clase" - I'm pretty sure the Cama option is private cabin, and would be just the two of us, right? Also, there are 3 choices with explanations in Spanish on the difference in the options, and I don't understand the difference! I'm thinking it's just based on option to cancel and/or change date?

Can anyone help? Thanks, really excited for my upcoming trek!

Thank you so much! So, seems best to purchase direct from "loco2.com" website - much more understandable and I know what I'm getting. Thanks!