( A ) $F_{2} > Cl_{2} > Br_{2} > I_2$ ; Oxidising power
( B ) $HI > HBr > HCl > HF$ ; Acidic property in water
( C ) $F_{2} > Cl_{2} > Br_{2} > I_2$ ; Electronegativity
( D ) $F_{2} > Cl_{2} > Br_{2} > I2$ ; Bond dissociation energy