The use of strain type insulators is made where the conductors are

The correct answer is: B. At intermediate anchor towers

Strain type insulators are used at intermediate anchor towers to support the weight of the conductors and to prevent them from sagging too low. They are also used to protect the conductors from damage from wind and ice.

Dead-end towers are used to terminate the conductors at the end of a line. They do not require strain insulators, as the conductors are not supported by the tower.

Option C is incorrect, as strain insulators are not used at dead-end towers.

Option D is incorrect, as strain insulators are used at intermediate anchor towers.