URGENTEEE, ES PARA HOY

Which of the following statements implicitly describes the character's personality?
a) Natalia is very outgoing and makes friends very easily.
b) Mark is usually very reserved but can open up once you get to know him.
c) She doesn't usually get into arguments, so it was strange to see her so upset.
d) It was only a matter of time before he started talking to the new kids, laughing like they had been friends for years.