Solution
Option 1 -> Discount offers and referral programs are effective promotional tools that attract new customers and incentivize existing ones to spread word-of-mouth.
Option 2 -> Increasing product prices is a pricing strategy, not a promotion strategy, and typically discourages purchases rather than encouraging them.
Option 3 -> Reducing product variety is a product line decision that limits customer choice and is not related to promotion activities.
Option 4 -> Closing outlets is a business contraction move that reduces market presence, opposite to what promotion aims to achieve.
Hence, Option 1: Discount offers and referral programs -> These are proven promotional tactics that drive customer acquisition and retention by offering value incentives and leveraging customer networks to expand reach -> correct