What type of joints connect the drive shaft in rear-wheel drive vehicles?

The correct choice is universal joints (U-joints), which play a crucial role in the drivetrain of rear-wheel drive vehicles. These joints are specifically designed to allow rotational movement and flexibility in the drive shaft while accommodating changes in the angle of the drive shaft relative to the transmission and differential. This is essential because the drive shaft operates at varying angles as the vehicle moves over uneven terrain or during turns.

Universal joints enable the drive shaft to transmit power from the transmission to the rear axle effectively, ensuring smooth power delivery and minimizing vibrations. Their design allows for the necessary flexibility needed in a rear-wheel drive system while maintaining a robust connection.

Ball joints, hinge joints, and fixed joints serve different mechanical functions and do not provide the necessary flexibility for drivetrain applications like those found in rear-wheel drive vehicles. Ball joints are typically used in suspension systems to allow for vertical movement while maintaining stability. Hinge joints provide a single axis of rotation, which is not suitable for the multidirectional movement required by a drive shaft. Fixed joints do not allow for any movement and thus cannot accommodate the varying angles present in a rear-wheel drive layout.