Final answer:
Complementary strategic alliances come in two major types: horizontal and vertical (option a). Horizontal alliances are mergers between firms in the same market, while vertical alliances involve companies at different stages of production.
Step-by-step explanation:
The two major types of complementary strategic alliances are vertical and horizontal alliances. A horizontal merger occurs when two or more firms within the same product space or market join forces. This can be for various strategic reasons such as company growth, efficiency improvement, acquisition of new product lines, elimination of competitors, or to lose corporate identity. Horizontal mergers often face scrutiny under antitrust laws due to the reduction in competition they can cause.
On the other hand, a vertical merger involves companies at different stages of the production process. For example, a manufacturer might merge with a supplier or distributor to protect against the loss of essential components of its supply chain and to streamline manufacturing. This can increase the efficiency and control over the product lifecycle.