The __ is the LEAST common type of drum brake system in modern automotive use. Select one: a. Twin leading shoe drum brake system b. Leading/traling shoe drum brake system c. Duo-servo drum brake system d. None of the answers listed

The correct answer is a. Twin leading shoe drum brake system.<br /><br />In modern automotive use, the twin leading shoe drum brake system is the least common type of drum brake system. This system uses two leading shoes that move in the same direction during braking, providing less braking force compared to other drum brake systems. The leading/trailing shoe drum brake system and the duo-servo drum brake system are more commonly used in modern vehicles due to their higher braking efficiency and reliability.