Final answer:
Direct sales force provides the most control over distribution channels but at higher costs, offering significant control but requiring substantial investment.
Step-by-step explanation:
Of the distribution modes listed, Direct sales force affords the most control over distribution channels. A direct sales force implies that a company uses its own employees to carry out the sales process, which provides a high degree of control. However, this level of control comes at a higher cost due to expenses such as salaries, training, benefits, and the infrastructure needed to support a sales team. Other modes such as export associations, trading companies, and export management companies offer various degrees of market-based mechanisms, while complementary marketers may involve some form of partnership or collaboration, providing less control than a direct sales force.