Molecules, which have the same chemical formula and bond connectivity but different relative arrangement in three- dimensional space is called (a) Enantiomers

(b) Stereoisomers

(c) Diastereomers

(d) Constitutional isomers​

B

Explanation:

Stereoisomers have the same connectivity in their atoms but a different arrangement in three-dimensional space. There are different classifications of stereoisomers depending on how the arrangements differ from one another. Notice that in the structural isomers, there was some difference in the connection of atoms. For example, 1-butene has a double bond followed by two single bonds while 2-butene has a single bond, then a double bond, then a single bond. A stereoisomer will have the same connectivity among all atoms in the molecule.

the awnser is group 12