A group 13 element 'X' reacts with chlorine gas to produce a compound XCl₃. XCl₃ is electron deficient and easily reacts with NH₃ to form Cl₃X $$ \leftarrow $$ NH₃ adduct ; however, XCl₃ does not dimerize X is :

When XO₂ is fused with an alkali metal hydroxide in presence of an oxidizing agent such as KNO₃ ; a dark green product is formed which disproportioates in acidic solution to afforda dark purple solution. X is :

The correct match between items of List - I and List - II is :

List - I		List - II
(A)	Phenelzine	(P)	Pyrimidine
(B)	Chloroxylenol	(Q)	Furan
(C)	Uracil	(R)	Hydrazine
(D)	Ranitidine	(S)	Phenol

For standardizing NaOH solution, which of the following is used as a primary standard ?