Explanation:

Recently, British physicist Dr Roger Penrose was awarded half the Nobel Prize in Physics this year for his work on black holes. But his work stands on the shoulders of Kolkata-born physicist Amal Kumar Raychaudhuri.

• The Raychaudhuri Equation in General Relativity, derived by Raychaudhuri, has now come into the spotlight. The Raychaudhuri Equation, a fundamental result in general relativity, describes how nearby bits of matter move.
• It was discovered independently by Raychaudhuri and Soviet physicist Lev Landau as a simple, general validation of our expectation that gravitation is a universal force that attracts objects with mass and energy according to the General Relativity theory (and Newton's theory of gravitation).
• The Raychaudhuri Equation continues to be a key tool in investigating the behaviour of black hole horizons in modern physics.

Hence option 2nd is correct.