Step 1: Understanding the history of Metro systems in India.
India’s metro systems began in the late 20th century to ease urban transportation.
Step 2: Identifying the Oldest Metro.
Kolkata Metro is the oldest metro system in India, which began operations in 1984.
Step 3: Verifying the Options.
Option (1): Delhi Metro is one of the most modern and largest metro systems, but it was inaugurated in 2002.
Option (2): Kolkata Metro is the oldest, established in 1984.
Option (3): Chennai Metro is relatively new, launched in 2015.
Option (4): Mumbai Metro began operations in 2014.