British consolidated their hold on which three nodes?

Mumbai, Kolkata, Chennai

The correct answer is Option (3) → Mumbai, Kolkata, Chennai

Modern Towns: The British and other Europeans have developed a number of towns in India. Starting their foothold on coastal locations, they first developed some trading ports such as Surat, Daman, Goa, Pondicherry, etc. The British later consolidated their hold around three principal nodes – Mumbai (Bombay), Chennai (Madras), and Kolkata (Calcutta) – and built them in the British style. Rapidly extending their domination either directly or through control over the princely states, they established their administrative centres, hilltowns as summer resorts, and added new civil administrative and military areas to them. Towns based on modern industries also evolved after 1850. Jamshedpur can be cited as an example.