Stereoisomers which are not the mirror images of one another are called

The specific rotation of $(+)$-Mandelic acid is $+158^o$. What will be the specific rotation of a mixture containing $25\%$ $(-)$-Mandelic acid and $75\%$ $(+)$-Mandelic acid?

The chiral compounds among the following are:

How many chiral carbons are present in $1, 2-$dichlorocyclohexane?

Given below are two statements.
Statement $I$: The compound shown below is optically active.
[Image of compound $A$]
Statement $II$: The compound shown below is the mirror image of the above compound $A$.
[Image of compound $B$]
In the light of the above statements,choose the most appropriate answer from the options given below.

Which of the following are enantiomers?