Consider the reactions and identify $A, X, Y$ and $Z$:
$X (C_2H_6O)$ $\xrightarrow{Cu, 573 \ K} A$ $\xrightarrow{[Ag(NH_3)_2]^+, ^-OH, \Delta} \text{Silver mirror}$
$A \xrightarrow{^-OH, \Delta} Y$
$A \xrightarrow{NH_2NHCONH_2} Z$

• A
  $A: \text{Methoxymethane}, X: \text{Ethanol}, Y: \text{Ethanoic acid}, Z: \text{Semicarbazide}$
• B
  $A: \text{Ethanal}, X: \text{Ethanol}, Y: \text{But-2-enal}, Z: \text{Semicarbazone}$
• C
  $A: \text{Ethanol}, X: \text{Acetaldehyde}, Y: \text{Butanone}, Z: \text{Hydrazone}$
• D
  $A: \text{Methoxymethane}, X: \text{Ethanoic acid}, Y: \text{Acetate ion}, Z: \text{Hydrazine}$