Explanation

(c)
The compound which contains $–COCH_{3}$ group in its structure, give positive iodoform test and the compound which contains $–CHO\$group give positive Fehling test.
In ethanal, $CH_{3}CHO$ both the groups are present, hence it responds to both iodoform test and Fehling’s test.
$CH_{3}CHO + I_{2} + NaOH \rightarrow CHI_{3} + NaI + H_{2}O$
iodoform
$CH_{3}CHO + Cu(OH)_{2} \rightarrow CH_{3}COOH + Cu_{2}O \downarrow + 2H_{2}O$
Fehling’s red ppt.
Solution