The optical phenomenon that allows us to view rapidly changing still images as moving images is called
a persistence of vision
b eternal vision
c 20/20 vision
d none of the above

a) Persistence of vision

Explanation: Persistence of vision is defined as the phenomena in which many different still images are mixed togather to form one image that can act as illusion in the mind of human being .This phenomena is presented in the form of perception of motion that causes the optical illusion.

Other options are incorrect because eternal vision is referred as the infinity vision by god.20/20 vision is the normal vision measured from 20 feet to determine the  accuracy. Thus, the correct option is option(a).