A company that sells building materials buys a quarry. Which strategy is applied?

Forward vertical integration occurs when a company expands its operations by acquiring businesses at the next stage in the supply chain, such as distributors or retailers. In this scenario, the company is not moving forward to the customer; instead, it is acquiring a source of raw materials, which does not align with this strategy.

Vendor-managed inventory (VMI) is a supply chain strategy where the vendor is responsible for managing the inventory of their products at the customer's location. This choice does not apply to the situation described, as it pertains to inventory management rather than the acquisition of a resource or supplier.

A lean supply chain focuses on minimizing waste and maximizing efficiency throughout the production and distribution process. While it's a valuable strategy, it does not specifically address the acquisition of a quarry, which is a clear example of backward vertical integration.