Use bond-counting (O > C > H; C-C bonds count zero) for the sequence ethanol, ethanal, ethanoic acid. Select the correct statements.

1. AThe $\mathrm{CH}{}_2\mathrm{OH}$ carbon of ethanol is $-1$
2. BThe carbonyl carbon of ethanal is $+1$
3. CThe carboxyl carbon of ethanoic acid is $+3$
4. DThe methyl carbon changes from $-3$ to $-4$ during the sequence