Which of the following gives a red precipitate of $\mathrm{Cu}{}_2\mathrm{O}$ on warming with Fehling's solution?

Fehling's solution oxidises aliphatic aldehydes, and the $\mathrm{Cu}{}^{2+}$ is reduced to red $\mathrm{Cu}{}_2\mathrm{O}$. Aromatic aldehydes and ketones do not respond. Propanal is the only aliphatic aldehyde listed.