"Usher rose from a sofa on which he had been lying at full length, and greeted me with a vivacious warmth which had much in it"
In this line, Usher's behavior of rising from the sofa to greet the narrator is a sign of friendly hospitality even though it seems as he rarely gets up from the sofa. Also, the narrator describes his greeting as vivacious. Vivacious means full of life and energy. This is in complete contrast to what we learn about Roderick Usher.While Usher is glad his friend has come, he is not full of life or energy.
It would be his hunger, thirst, and suffocation in the train car. The other options are internal conflicts because they are occurring inside his head and are emotions or thoughts.
