Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R:

Assertion A: $$\mathrm{H}_2 \mathrm{Te}$$ is more acidic than $$\mathrm{H}_2 \mathrm{~S}$$.

Reason R: Bond dissociation enthalpy of $$\mathrm{H}_2 \mathrm{Te}$$ is lower than $$\mathrm{H}_2 \mathrm{~S}$$.

In the light of the above statements, choose the most appropriate from the options given below:

Alkaline oxidative fusion of $$\mathrm{MnO}_2$$ gives "A" which on electrolytic oxidation in alkaline solution produces B. A and B respectively are

Salicylaldehyde is synthesized from phenol, when reacted with

m-chlorobenzaldehyde on treatment with 50% KOH solution yields :