A test consists of 3 multiple choice questions.

Each question has 2 choices (A or B), with exactly one correct choice.

A completely unprepared participant guesses on each of the 3 multiple choice questions.

Let x = number of times the participant selects choice A.

Assume that the participant selects the choices independently of one another and that the two choices are equally likely to be selected. What is the probability that choice A is chosen at most one time?