The correct answer is Electric vehicle services. Explanation & Key Takeaways: • In May 2025, the Reserve Bank of India (RBI) initiated a rigorous audit and review of digital wallets specifically linked to the Electric vehicle services sector. • The move was prompted by the sudden operational shutdown of BluSmart, which was a major player in the EV ride-hailing and charging infrastructure ecosystem. • The central bank's intervention focused on the Prepaid Payment Instruments (PPI) used by EV service providers to manage customer balances for ride bookings and battery charging. • The investigation aimed to determine if Electric vehicle services providers were maintaining escrow accounts correctly to safeguard user deposits, as mandated by the Payment and Settlement Systems Act. • This regulatory action highlights the RBI's concern regarding the financial stability of fintech-integrated mobility platforms and the protection of consumer interest in the event of corporate insolvency. Related Concepts: • Electric Vehicle Services: This industry encompasses e-mobility solutions, including electric cabs, bike-sharing, and public charging stations. These services often require users to maintain a "walled garden" balance in a closed-loop or semi-closed-loop wallet. • BluSmart: Recognized as a pioneer in all-electric ride-sharing in India, it operated a large fleet and massive charging hubs. Its closure in the 2025 timeline created a ripple effect in the green mobility market, leading to concerns over unrecovered user funds. • PPI Guidelines: The Reserve Bank of India issues Master Directions on Prepaid Payment Instruments, which regulate how companies can issue wallets and how they must store the money received from the public. • Digital Payment Ecosystem: The integration of fintech within Electric vehicle services is part of a broader trend to streamline micro-transactions, though it introduces new layers of regulatory risk that the RBI monitors closely. Important Notes: • Consumer Redressal: Following the BluSmart incident, the RBI emphasized that Electric vehicle services must have a transparent refund mechanism for any unutilized balances stored in digital wallets. • Interoperability: A key feature discussed during the 2025 review was the potential requirement for wallet interoperability, allowing EV users to transfer balances between different charging or ride-hailing service providers. • Compliance Audits: Companies in the EV sector are now required to submit periodic System Audit Reports (SAR) to the RBI to ensure their digital payment infrastructure meets cybersecurity and financial safety standards. • Financial Solvency: The central bank has suggested that non-banking entities in the Electric vehicle services space might need to maintain higher net worth requirements to continue offering wallet-based services.