Which of the following compound has highest enol content?
The answer is an option (c) and I think the reason behind it is that there are two phenyl groups attached to it, hence there will be a good conjugation. Also, since phenyl is an electron-withdrawing group, it will provide stability to the structure (as the $\ce{C-C}$ double bond formed after tautomerism will have π-electrons). But I am not quite sure about my logic and I don't know the reasons to eliminate other options.