This is a classic decision-making question about weighing a company's short-term interest, protecting its image and profit, against its real duty toward customers who bought a defective product. The right choice is the one that best protects the customers while still being fair to the company's long-term standing.
Compared with all of these, openly apologizing and fixing the bug for every customer directly removes the harm at its source and treats every customer the same way, even though it costs the company money in the short run. A short-term financial hit is a smaller price than losing customer trust permanently once a cover-up eventually comes out, which is what would happen with any of the silent options.
Let's summarize:
So the best choice is to apologize and fix the bug for all customers, which is option 1.