Explanation:

- Juan Manuel Santos, the former President of Colombia, was honored with the Nobel Prize in 2016.

- His accolade was specifically in recognition of his efforts in a significant area.

- Option 1: Chemistry - This award is for discoveries in molecular sciences, which was not Santos's endeavor.

- Option 2: Peace - This is the correct field. Santos was awarded the Nobel Peace Prize for his resolute efforts to end the long-running civil war with the FARC guerrillas in Colombia, marking a step toward peace in the nation.

- Option 3: Physics - Recognizes advances in physical sciences, unrelated to Santos.

- Option 4: Medicine - Awards life sciences breakthroughs, not related to Santos’s contributions.