Reading Comprehension — quick quiz

Passage: India's digital payment ecosystem has witnessed remarkable growth in recent years. The Unified Payments Interface (UPI) has emerged as the backbone of digital transactions, processing over 10 billion transactions monthly by 2023. This growth has been driven by increased smartphone penetration, affordable data plans, and government initiatives promoting cashless transactions. Small merchants and street vendors have also adopted digital payments, making it accessible across urban and rural areas. However, concerns about data security and digital literacy remain challenges that need continuous attention. Question: According to the passage, what has been the primary driver behind the growth of digital payments in India?