Question

in order to stop the spread of industrial technology, britain
closed companies suspected of sharing secrets.
penalized companies harshly for any hint of a leak.
searched for spies in all industrial and manufacturing companies.
forbade mechanics, engineers, and others from leaving the country.

Explanation:

During the Industrial Revolution, Britain aimed to maintain its technological advantage by restricting the outflow of skilled workers with knowledge of industrial processes. Forbidding mechanics, engineers, and similar professionals from leaving the country directly prevented them from taking industrial secrets abroad to competing nations.

Answer:

D. forbade mechanics, engineers, and others from leaving the country.