Which one of the following reactions will not result in the formation of a carbon-carbon bond?

What type of product is obtained when formaldehyde reacts with $CH_3MgBr$ in dry ether?

The reddish brown precipitate formed in the Fehling's test for aldehydes $(RCHO)$ is due to the formation of

$A \xrightarrow{} (CH_3)_2C=CH-CO-CH_3$. $A$ is:

The given reaction is an example of an intramolecular aldol condensation. Identify the product $(A)$ formed in the reaction:
$1,5-\text{cyclooctanedione} \xrightarrow{H_2SO_4, H_2O} (A)$

Some organic compounds possess fragrance and taste. Their names are given in Column-$I$,structures in Column-$II$,and their sources in Column-$III$. Match Column-$I$ with Column-$II$ and Column-$III$.

Column-$I$ (Name)	Column-$II$ (Structure)	Column-$III$ (Source)
$(A)$ Vanillin	$(i)$ $C_6H_4(OH)CHO$ (ortho)	$(p)$ From cinnamon
$(B)$ Salicylaldehyde	$(ii)$ $C_6H_5CH=CHCHO$	$(q)$ From seeds of vanilla
$(C)$ Cinnamaldehyde	$(iii)$ $C_6H_3(OH)(OCH_3)CHO$	$(r)$ From meadow sweet