Which of the following give a yellow precipitate of iodoform on warming with $\mathrm{I}{}_2$ and aqueous $\mathrm{NaOH}$?

A positive test needs $\mathrm{CH}{}_3-\mathrm{CO}{}^{-}$ attached to H or C, or a $\mathrm{CH}{}_3-\mathrm{CH}(\mathrm{OH}){}^{-}$ group that hypoiodite oxidises to it. 1-Phenylethan-1-ol is $\mathrm{C}{}_6\mathrm{H}{}_5\mathrm{CH}(\mathrm{OH})\mathrm{CH}{}_3$ and ethanal is $\mathrm{CH}{}_3\mathrm{CHO}$. Pentan-3-one has $\mathrm{CH}{}_3\mathrm{CH}{}_2-\mathrm{CO}{}^{-}$ (no methyl on the carbonyl) and 2-methylpropan-1-ol is a primary alcohol with no $\mathrm{CH}{}_3\mathrm{CH}(\mathrm{OH})$ unit.