Answer:
B) If the IAR receives authority via telephone and this is followed by written authority within 10 days, the IAR may exercise discretion over the account.
Explanation:
The members of the North American Securities Administrators Association (NASAA) must follow their Model Rule which allows IAR the use of discretionary authority with verbal authorization (in this case a telephone call), but the verbal authorization must be confirmed by a written authorization within 10 days.