Explanation:

- Option 1: Gorbachev

- Mikhail Gorbachev was a Soviet leader, not primarily known as a labor leader.

- He won the Nobel Peace Prize in 1990 for his role in ending the Cold War.

- Option 2: Lech Walesa

- Lech Walesa was a Polish labor leader and co-founder of Solidarity, the first independent trade union in the Soviet bloc.

- He was awarded the Nobel Peace Prize in 1983 for his efforts in leading the Solidarity movement, which promoted social change through nonviolent means.

- Option 3: G. Ramanujan

- Srinivasa Ramanujan was a mathematician, not related to labor movements or Nobel Prize recognition.

- Option 4: None of the above

- This option is incorrect as Lech Walesa is the correct choice.