Which of the following compounds show tautomerism?

Tautomerism is isomerism in which the isomers are readily interchangeable and are in dynamic equilibrium with each other.

α-hydrogen. Keto compounds show tautomerism.

Tautomerism is a phenomenon where a single chemical compound tends to exist in two or more interconvertible structures.

Those are different in terms of the relative position of one atomic nucleus which is generally the hydrogen.

Tautomers are a type of isomers that have a different compound only in the case between protons and electrons. The carbon structure of this compound has not changed. A chemical reaction with a simple proton transfer of a proton to a different molecular structure is called Tautomerism.

Correct answer is options (a, b, c, d).