Q. Assertion (A) The compounds that have the same constitution and sequence of covalent bonds but differ in relative positions of their atoms or groups in space are called stereoisomers.
Reason (R) Stereoisomerism is a special type of isomerism which can be classified as geometrical and optical isomerism.

 351  167 Organic Chemistry – Some Basic Principles and Techniques Report Error

Solution:

The compounds that have the same constitution and sequence of covalent bonds but differ in relative position of their atoms or groups in space are called stereoisomers. This special type of isomerism is called stereoisomerism and can be classified as geometrical and optical isomerism.
Thus, both and are correct and is not the correct explanation of .