Which method provides the ability to connect at an angle to the driving shaft?

Universal joints are specifically designed to allow for the transmission of torque and rotation between two shafts that are not in a straight line with each other, making them ideal for connecting at an angle. They are used frequently in applications where the driving shaft and the driven shaft are misaligned, accommodating angular and even axial movement. This flexibility is essential in many mechanical systems, such as automotive drive trains, where components must connect dynamically while allowing for movement and varying angles.

In contrast, couplings generally serve to join two shafts that are aligned and do not provide the same angular flexibility that universal joints do. Clutches primarily function to engage or disengage power transmission rather than to connect shafts at angles, while coaxial connectors are used in electrical and data transmission systems, not mechanical shaft connections. Thus, the unique capability of universal joints to accommodate angle variations in shaft alignment is what makes them the correct choice in this scenario.