Which of the following actions is a clear example of horizontal integration?

A railroad company purchasing coal mines to fuel its locomotives.

A large social media company acquiring a smaller, competing social media app.

A clothing manufacturer buying the farms that grow the cotton for its fabrics.

An automobile maker investing in a new division to produce electric scooters.

Which of the following best defines the strategy of horizontal integration?

Owning the entire supply chain.

Expanding into unrelated industries.

Forming partnerships with rival firms.