According to nature of current, distribution system may be classified as :

(i) DC distribution system

(ii) AC distribution system

Now-a-days, ac system is universally adopted for distribution of electric power as it is simpler and more economical than direct current method.

According to type of construction distribution system may be classified as :

(i) Overhead system

(ii) Underground system

According to scheme of connection, the distribution system may be classified as :

(i) Radial system

(ii) Ring-main system

(iii) Inter-connected system

Hence, the correct option is (B).