Yes, all of these affect how easily students can learn the pronunciation of a new language. People who tend to be more willing to accept new things, who don't mind being daring and different, and people who really want to learn will probably have an easier time of it. Young children generally learn new pronunciation more easily than adults. (Lucky children!) And the sounds, rhythm, and intonation patterns of a student's own language certainly affect how they'll learn the sounds of a new language. (If you chose A, B, or C, you're actually correct too!)