Extraction of Mg from sea water

Which of the following option describes the correct reactant, products and reaction conditions? 

	p	q	r	s	t
A)	Milk of magnesia	$HC\mathcal{l}\left(aq\right)$	$MgC{l}_2.2H_{2}O$	Heating in limited supply of air	Reduction by coke
B)	Lime water	$HC\mathcal{l}\left(aq\right)$	$MgC{l}_2$	Heating in absence of air	Electrolytic reduction in molten state
C)	Milk of lime	$HC\mathcal{l}\left(aq\right)$	$MgC{l}_2.6H_{2}O$	Heating in presence of dry HCl	Electrolytic reduction in molten state
D)	Milk of lime	$HC\mathcal{l}\left(aq\right)$	$MgC{l}_2.6H_{2}O$	Heating in the presence of dry HCl	Electrolysis of aqueous solution