Select all of the chirality centers in the structure. a selected atom will turn green.

The answer is C is attached to four unique gatherings A, B C and D, Thus it frame two optical isomers as the perfect representations of one another.  

Explanation:

A critical class of isomers in which mixes have the equivalent sub-atomic recipe and structure, yet the distinction emerges from the introduction of the gatherings in the 3D space. Optical isomers are called as enantiomers.   Enantiomers are optical isomers whose identical representations are non-superimpose. They turn the plane enraptured light inverse way.   Optical action is characterized as the capacity of a choral atom to pivot the plane energized light. The enantiomers that pivots the plane energized light a clockwise way is called extraordinary, while the one that turns the plane spellbound light an anticlockwise way is called rotatory.  Basics  , Centrality is the major behind the optical movement of a natural atom.  Choral focus: A'C' particle in a particle turns into a choral focus when all the four valences of that molecule are fulfilled by synthetically unique gatherings.