Answer:
Therefore, option C - economic factors, is the correct option.
Step-by-step explanation:
Economic factors include rising product development costs, economies of scale in manufacturing and distribution, worldwide sourcing efficiency, steep learning curves, and significant differences in host-country costs.
The benefits gained by Swift Inc. relates to the economic factor of significant differences in the cost of the host country, Thailand.
Therefore, option C - economic factors, is the correct option.