In a reaction $\text{R}\mathrm{\text{C}}\mathrm{\text{H}}\mathrm{\text{O}}$ is reduced to $\text{R}\mathrm{\text{C}}{\mathrm{\text{H}}}_3$ using amalgamated zinc and concentrated $\mathrm{\text{H}}\mathrm{\text{Cl}}$ and warming the solution. The reaction is known as

Which of the following reactions is used for producing symmetrical alkane with double carbon atoms?

The aldehydes which will not form Grignard product with one equivalent of Grignard reagents are
$\left(\mathrm{A}\right)$

$\left(\mathrm{B}\right)$

$\left(\mathrm{C}\right)$

$\left(\mathrm{D}\right)$