Question

construction
jack stand construction is simple. usually, the base is relatively wide, providing stability.
the main difference between jack stands is the way in which they are locked. the total service height is adjustable.
a tubular type jack stand is locked with a steel pin. both the stand and the tube have holes drilled in them. by aligning the holes, the locking pin can be inserted.
the other jack stand has a toothed section which locks using a simple mechanical system. the mechanical section can only be lowered by operating the steel handle. this type usually has an extra locking pin for added safety.
how are these two jack stands different?
the design.
the function.
the locking system.

Explanation:

The text states that the main difference between the two jack - stands is the way they are locked. One is locked with a steel pin by aligning holes, and the other has a toothed section with a simple mechanical locking system. This indicates a difference in the locking system. Also, the different locking mechanisms imply differences in design. Since both are jack - stands for supporting vehicles, their basic function is the same.

Answer:

A. The design.
C. The locking system.