The greatest prime number that is a divisor of $16,384$ is $2$ because $16,384=2^{14}$. What is the sum of the digits of the greatest prime number that is a divisor of $16,383$ ? 
选项为:A:$$3$$  B:$$7$$  C:$$10$$  D:$$16$$  E:$$22$$  请回答其中一个选项.