The GPAs (grade point averages) of students who take the AP Statistics exam are approximately normally distributed with a mean of 3.4 and a standard deviation of 0.3. What is the probability that a student selected at random from this group has a GPA lower than 3.0? 
选项为:A:$$0.0918$$  B:$$0.4082$$  C:$$0.9082$$  D:$$-0.0918$$  E:$$0$$  请回答其中一个选项.