Capital deepening refers to?

Capital deepening is likely to be understood as a situation where the amount of capital per worker, or the capital-to-labor ratio, is increased. This typically occurs when firms invest in more advanced equipment or technology, allowing each worker to utilize more capital in their production activities. As a result, productivity tends to rise since workers are able to produce more output with the enhanced capital resources at their disposal.

In essence, option B captures this concept accurately by emphasizing the increase in the capital-to-labor ratio, which signifies that workers have more capital available to work with, leading to improved efficiency and production capabilities. This contrasts significantly with the other options that either represent a decrease in capital use or do not correctly illustrate the relationship between capital and labor in the context of deepening.