Which of the following carboxylic acids undergo decarboxylation easily

Which of the reagent is used to convert 2-Butanone into propanoic acid

Among the given compounds, the most susceptible to nucleophilic attack at the carbonyl group is

In the reaction sequence : A B Acetone C A, B and C are

(CH3)2C = CHCOCH3 can be oxidised to (CH3)2C=CH.COOH by -

CH3 – CH2 – CHO Product. The product in the above reaction is: