Question

industry has lowered its labor costs through
the use of tablet computers.
advances in robotics.
faster communications.
just - in - time manufacturing.

Explanation:

Advances in robotics can replace human labor in industry, reducing labor costs. Tablet computers are more for individual or office use in some cases rather than major labor - cost reduction in industry. Faster communications mainly aid in information transfer. Just - in - time manufacturing is more about inventory management rather than direct labor - cost reduction through labor substitution.

Answer:

advances in robotics.