One of the basic themes in Part 1 is that personal experience can be very

untrustworthy as a guide to the truth. An example is

(a) our visual perception is faulty, so the stars appear much further away than
they are
(b) our bodies cannot detect uniform motion, which means that we tend to
perceive the world as stationary
(c) placebo effects, such as in the study on speech anxiety
(d) both B and C are examples of the untrustworthiness of personal
experience

D