Final answer:
National Geographic remained profitable by expanding its television programming, investing in online content, and diversifying its merchandise.
Step-by-step explanation:
National Geographic remained profitable when its magazine started to lose circulation in the 1990s by expanding its television programming, investing in online content, and diversifying its merchandise.
By expanding its television programming, National Geographic was able to reach a wider audience and generate additional revenue through advertising and licensing deals. Investing in online content allowed the magazine to adapt to the digital age and attract new readers and subscribers. Diversifying its merchandise, such as selling books, DVDs, and other products, helped National Geographic generate income beyond magazine subscriptions.