Imagine You Are Staring at the Center of a Page

Multiple Choice

Imagine you are staring at the center of a page with one eye,and an X is elsewhere on the page.You move the page toward your eye and away,and at one location the X seems to disappear.Why?​

A) The lens cannot focus fast enough to compensate for the movement.​
B) ​You have a blind spot in your retina.
C) ​You fail to attend to an unchanging stimulus.
D) ​Your closed eye has inhibited input from the open eye.