Which of the following can show both tautomerism and optical isomerism

• Tautomer's are isomers of a compound which differ only in the position of the protons and electrons. 
• Molecules that exhibit tautomerism have the same molecular formula and they interconvert rapidly.
• The difference between the chiral and achiral molecules can be defined based on the symmetry plane. 
• If all the attached groups to the central carbon atom are different, then there exists no plane of symmetry. 
• Such a molecule is called a chiral molecule.
• If all the groups attached to the central carbon atom are not completely different, then there exists a plane of symmetry.
•  Such molecules are known as achiral molecules. 
• It is also clear that only the molecule having a chiral center will exhibit optical isomerism, which is shown below.

$* \mathrm{indicates} \mathrm{the} \mathrm{stereo} \mathrm{center}$