In a clinical​ trial, 18 out of 840 patients taking a prescription drug daily complained of flu-like symptoms. Suppose that it is known that ​1.8% of patients taking competing drugs complain of flu-like symptoms. Is there sufficient evidence to conclude that more than 1.8​% of this​ drug's users experience flu-like symptoms as a side effect at the a=0.01 level of​ significance?

a) Yes
b) No
c) Insufficient data
d) Statistical anomaly