Four species are listed below:<br> i. $HCO_3^{-}$ ii. $H_3O^+$ iii. $HSO_4^{-}$ iv. $HSO_3F$ <br> Which one of the following is the correct sequence of their acid strength?

Question

( A ) iv < ii < iii < I
( B ) ii < iii < i < iv
( C ) i < iii < ii < iv
( D ) iii < i < iv < ii