C. multiple downstream channels.
The corporate strategy described in the scenario involves the ability to switch the production line to a different product (commodity-type) and sell it on the open market at reduced terms to generate cash when demand for the original product drops. This strategy demonstrates having multiple downstream channels, as the company is able to pivot its production and sales to different products and markets based on changing demand conditions. This flexibility in product diversification and market access allows the company to adapt to changing customer needs and market conditions, which is indicative of a strategy that focuses on having multiple downstream channels.