Every Homologous series is characterised by certain type of reactions. Identify the correct match 

	Column - I (Homologous series)		Column - II (Type of reaction)
I)	Alkenes	a)	Nucleophilic substitution
II)	Aromatic Hydrocarbons	b)	Electrophilic addition
III)	Halo alkanes	c)	Nucleophilic addition
IV)	Carbonyl compounds	d)	Electrophilic substitution

	I	II	III	IV
1)	d	b	c	a
2)	c	d	b	a
3)	b	a	d	c
4)	b	d	a	c

In alkanes, double bonded carbon is sp² hybridized. They are electron rich specie and can undergo electrophilic addition reaction. In aromatic hydrocarbons, electrophilic substitution reaction is possible because if it undergoes electrophilic addition reaction, then its aromaticity is destroyed.

In haloalkanes, there is a partial positive charge on C atom (attached to the halogen) and nucleophilic easily attacks on the C and replaces the halogen. Therefore, haloalkanes undergoes nucleophilic substitution reaction.

In carbonyl compounds, carbonyl carbon atom is electron-deficient and hence, undergoes nucleophilic addition reaction.