Match the following specific retention strategies to the respective supply-side lever as outlined in the D2C brand retention framework:
- Strategy I: Implementing a system that includes regular product testing and customer feedback integration.
- Strategy II: Launching a seasonal product line that reflects current trends and customer preferences.
- Strategy III: Offering a loyalty program that provides progressive discounts on future purchases based on customer purchase history.
- Strategy IV: Providing scheduled delivery options that allow customers to choose exact delivery times for their convenience.
Match each strategy to one of these levers: Delivery, Pricing, Quality, Variety.