Answer

a

Explanation

`(A rarr R, S) HSO_(4)^(ɵ) + H_(2)O rarr H_(3)O^(o+) + SO_(4)^(2-)` (Bronsted base)
`HSO_(4)^(ɵ) + H^(o+) rarr H_(2)SO_(4)` (Bronsted base)
`(B rarr P)BF_(3)` (`e^(-)` deficient and hence Lewis acid). `(C rarr Q, S) H_(3)N` : (It can donate lone pair of electrons and acts as Lewis base)
`NH_(3) + H_(2)O rarr overset(o+)(N)H_(4) + overset(ɵ)(O)H` (Accepts `H^(o+)` and acts as Bronsted base)
`(D rarr Q, S) overset(ɵ)(O)H` (It is bronsted base by accepting `H^(o+)` It can donate lone pair of electrons and acts as Lewis base also.