Answer:
The correct answer is C) changeable.
Explanation:
Interpersonal communication skills are something we learn, gain and practice throughout our lifetime. We cannot say they are fixed because they can improve and deteriorate without any doubt, depending on if we work on them or not. They are not genetic due to the fact that every person can learn how to develop better interpersonal communication skills. We cannot treat them as impractical knowing that they upgrade the relationship we have with other people. So, the only correct and the only possible answer is changeable.