Answer:
B. biological predisposition
Step-by-step explanation:
Social anxiety disorder is a disorder that causes more than normal amounts of anxiety when confronted with social situations. Social anxiety can disrupt a person's life. It lead to the development of low self esteem, not being able to be assertive, talking negatively about yourself, being affected by criticism etc.
It is highly likely that a person may have social anxiety disorder if his/her parents have the disorder i.e., it is inherited. This means that a major risk factor for developing a social anxiety disorder is biological predisposition.