Explanation:

Let’s break this down:

- The Einstein Prize is given by the American Physical Society. It specifically recognizes outstanding achievements in gravitational physics.

- Abhay Ashtekar (Option 1) is an Indian theoretical physicist known for his work in loop quantum gravity.

- Peter Bergmann (Option 2) was a well-known physicist who worked on general relativity, but he didn’t win the 2018 Einstein Prize.

- John Wheeler (Option 3) was another legend in theoretical physics, especially in black holes and relativity, but not the 2018 laureate.

- William Nordhaus (Option 4) is an economist who won the 2018 Nobel Prize in Economics, not the Einstein Prize.

The person who actually received the Einstein Prize in 2018 is Abhay Ashtekar.