Read the passage carefully and answer the Questions
Aldehydes and ketones are important organic compounds prepared mainly by oxidation of alcohols. Primary alcohols give aldehyde and secondary alcohols yield ketones. Aldehydes can also be formed by partial reduction of acid chlorides, reduction of esters or by Gattermann-Koch reaction. Ketones are prepared by Friedel-Craft's acylation, hydration of alkyne and reaction of Grignard's reagent with nitriles. Chemically, aldehydes and ketones are reactive in nature due to the carbonyl group and undergo nucleophilic addition reactions. Aldehydes are more reactive than ketones and can be oxidized to carboxylic acids, while both can be reduced to alcohols or hydrocarbons and exhibit condensation reaction
The correct IUPAC name of Vanillin is

1. A 4-Hydroxy-3-methoxybenzaldehyde
2. B 3-Methoxy-4-hydroxybenzaldehyde
3. C 3-Hydroxy-4-methoxybenzaldehyde
4. D 4-Methoxy-3-hydroxybenzaldehyde