"I like sitting than standing," is not a complete English sentence, so it should not be listed as a correct response. The word "more" is not optional in the comparison, which should read "I like sitting more than standing." For the Esperanto sentence, "Mi pli ŝatas sidi ol stari," I awkwardly transliterated with "I more like sitting than standing," which was marked wrong, but it was only stylistically awkward, not wrong.
Mi amas ĉi tiun kurson, so I am only trying to help, not be a pest.
The following sentences would be correct and close to your sentence:
I prefer sitting more than standing. I prefer sitting rather than standing. I prefer sitting instead of standing. I prefer sitting over standing. (My preference for sitting over-weighs my preference for standing.) I prefer sitting to standing. (I prefer sitting in comparison to standing.)
And by changing the verb forms, you can get other possibilities:
I prefer to sit more than to stand. I would rather sit than stand. Etc.
I fear for anyone learning English--I would not want to do it if I were not a native speaker. So, I hope that I have helped you a little.