Which integration strategy involves primary businesses starting to manufacture goods?

The correct answer is based on the concept of integration strategies in business. When primary businesses start to manufacture goods, this typically involves a shift in their operations to create products rather than only extracting or sourcing raw materials. This is a key characteristic of backward integration.

Backward integration is a strategy where a company expands its role to include the production of inputs it previously purchased. For example, a primary business that traditionally sources materials may choose to start manufacturing those materials in-house, allowing it to reduce costs, gain more control over the supply chain, and potentially improve product quality.

In contrast, forward integration would involve a company moving towards the end-user by acquiring or controlling distribution channels, while horizontal integration refers to a company expanding its reach within the same industry, often by acquiring competitors or merging with similar companies. Therefore, backward integration best describes the scenario of a primary business taking steps to manufacture its goods.