Which of the following compounds will undergo self aldol...

Aldehydes which contain $\alpha$-hydrogen on a saturated carbon, i.e. $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CHO}$ will undergo aldol condensation. Although $\mathrm{CH}_2=\stackrel{\alpha}{\mathrm{C}} \mathrm{H}-\mathrm{CHO}$ also contain a $\alpha$-hydrogen atom but cannot be easily abstracted by a base to form a carbanion and hence does not undergo aldol condensation.