Which of the following is used to distinguish ethylene and acetylene?

$HC \equiv CH$ $\xrightarrow[{excess}]{{CH_3MgBr}} \mathop {(A)}\limits_{\text{salt}} + \mathop {(B)}\limits_{\text{hydrocarbon}}$
$(A)$ $\xrightarrow[{excess}]{{CH_3I}} (C)$ $\xrightarrow[{(ii) H^{+} }]{{(i) NaNH_2}} (D)$

Which of the following reactions will yield $2,2$-dibromopropane as the product?

Which of the following is Lindlar catalyst?

Maximum bond energy of $C-H$ bonds is found in the compound:

What will be $X$ in the following reaction?
${C_2}{H_2} \xrightarrow[{HgSO_4 / H_2SO_4, 60^{\circ}C}]{{H_2O}} X \rightleftharpoons CH_3CHO$