Please read the short article and answer the question

United Technologies Corp. doubled down on the aerospace market with an all-stock deal to merge with defense contractor Raytheon Co., after UTC executives earlier chose to exit the escalator and air-conditioner businesses. The proposed deal intensifies the consolidation in the aerospace-and-defense industry as plane makers seek better terms from suppliers and the Pentagon puts more pressure on contractors to cut costs and invest more of their own money in new technologies, such as space systems and cybersecurity.

The new company will be named Raytheon Technologies Corp., and executives on Sunday called the deal, which doesnt include a takeover premium, a merger of equals. Executives said the merger would allow them to boost research spending and squeeze out some $1 billion in annual costs from the marriage. The tie-up would complete a radical transformation at UTC, a once sprawling conglomerate that already plans to spin off its Otis elevator and Carrier building-systems businesses into separate companies.

UTC makes engines, landing gear and other parts for commercial and military planes. Raytheon produces missiles such as the Tomahawk together with Patriot missile-defense systems, radars and other electronic-warfare systems. There is minimal overlap for the two companies, said Ms. Kahyaoglu. The companies could mutually benefit from their separate expertise, she said, such as leveraging UTCs expertise in global positioning systems across Raytheons missile programs.

A major defense industry merger has the benefits of providing economy of scale, making its supply chain leaner and creating an export powerhouse. But it can also threaten stagnation of research and development and make prices creep up at home, said Gregory Sanders, a deputy director at the Center for Strategic and International Studies, a Washington-based think tank. A market behemoth may be good at selling hardware, but fewer competitors mean that prices across the board can go up, which can be a problem for the main customer: the U.S. taxpayer.

In this article, we see that both United Technologies Corp. and Raytheon Co. are in the aerospace industry. Which of the following illustrates the type of diversification of the merger for United Technologies Corp.?

Forward integration

Unrelated Diversification

Portfolio Management

Backward integration