The company's decision to sell old oil drilling equipment and pipelines while investing in updated equipment for the processing factory indicates that they have chosen to focus on a specific area of their operations where they may see more potential for profit or efficiency. This suggests that they are concentrating their resources and efforts on the processing aspect of their business, rather than the upstream activities of drilling and transportation.
Given these considerations, the best answer is:
b. They decided to specialize.
This reflects their shift in strategy to concentrate on a narrower part of their business, likely in response to the losses they experienced in the drilling and transport segments.