How many different stereoisomers are possible for the given molecule?
The given molecule can exist as 4 stereoisomers:
two cis-trans isomers and two enantiomers (R and S). Hence, there are 4 possible stereoisomers. Thus, the correct answer is \( \boxed{4} \).
Assertion (A): All naturally occurring \(\alpha\)-amino acids except glycine are optically active. Reason (R): Most naturally occurring amino acids have L-configuration.