In a reaction, 

Reagents 'X' and 'Y' respectively are:

A

$$(CH_3CO)_2O/H^+$$ and $$CH_3OH/H^+, \Delta$$

B

$$(CH_3CO)_2O/H^+$$ and $$(CH_3CO)_2O/H^+$$

C

$$CH_3OH/H^+, \Delta$$ and $$CH_3OH/H^+, \Delta$$

D

$$CH_3OH/H^+, \Delta$$ and $$(CH_3CO)_2O/H^+$$