Alkyl halides are considered to be very reactive compounds towards nucleophile because:

Explanation

Option B is correct.Alkyl halides are considered to be very reactive compounds towards nucleophiles because they have an electrophilic carbon and a good leaving group. An electrophilic carbon is a carbon atom that has a partial positive charge. This partial positive charge makes the carbon atom more susceptible to attack by a nucleophile, which is an electron-rich species. A good leaving group is an ion that can easily leave a molecule without causing much disruption to the molecule. A good leaving group is usually a negatively charged ion with a relatively small size. In the case of alkyl halides, the halogen atom is the leaving group. The halogen atom is a good leaving group because it is negatively charged and has a relatively small size. When an alkyl halide reacts with a nucleophile, the nucleophile attacks the electrophilic carbon atom, displacing the halogen atom. This reaction is called a nucleophilic substitution reaction.