Janet Is Called for Jury Duty and Is Selected for Possible

Janet is called for jury duty and is selected for possible service on a jury. However, when the defendant's attorney sees her, he notices that she is wearing a green dress. Both the defendant and the defendant's attorney hate green dresses, so they strike her name from the jury. This is:

A) a valid challenge for cause.
B) a valid peremptory challenge.
C) not a valid challenge.
D) a valid challenge for cause, but it can be overcome if the plaintiff's attorney makes an offer of proof to the judge.