Which of the following are systematic errors?
a. A colorblind person who repeatedly runs red lights.
b. An accountant whose occasional math errors are sometimes on the high side and sometimes on the low side.
c. The tendency many people have to see faces in clouds.
d. Miranda paying good money for a nice-looking apple that turns out to be rotten inside.
e. Elvis always wanting to save more but then spending his whole paycheck, month after month.