Which of the following frame designs are no longer used in automobile manufacturing?

The ladder frame design has become less common in modern automobile manufacturing, particularly for passenger vehicles. Traditionally, a ladder frame consists of two parallel beams connected by cross members, creating a structure resembling a ladder. While this design offers high strength and is advantageous for commercial vehicles and trucks, advances in automotive technology and shifts in design philosophy have led to the adoption of more efficient alternatives for most passenger cars.

Unibody and monocoque designs, which integrate the vehicle's frame and body into a single unit, provide significant weight savings and improved structural rigidity. Space frames also remain relevant in specific applications, particularly in sports cars and high-performance vehicles, due to their high strength-to-weight ratios.

The move away from ladder frames reflects the industry's focus on fuel efficiency, safety, and performance, which are better supported by the modern frame designs that emphasize aerodynamics and overall vehicle dynamics.