Explanation

The Price-to-Sales (P/S) ratio is the least prone to distortion or manipulation in this scenario because:

• P/E ratio: Highly susceptible to manipulation since earnings can be distorted through aggressive capitalization of R&D expenses and operating expense manipulation
• P/B ratio: Can be affected by asset valuation and capitalization policies
• P/S ratio: Sales/revenue is generally harder to manipulate than earnings or book value, making P/S the most reliable multiple when earnings quality is questionable

When a company aggressively capitalizes R&D expenses, it artificially inflates earnings and assets while understating expenses. Sales figures are typically less affected by such accounting manipulations, making P/S the most robust multiple in this situation.