The correct answer is option 3, Jahangir. During the reign of Jahangir, the Mughal paintings reached their zenith or peak. Mughal painting is a style of art that emerged in India during the Mughal Empire, which lasted from the 16th to the 19th century.

Option 1, Babar, is incorrect as he was the founder of the Mughal Empire and his reign marked the beginning of Mughal rule in India. However, it was during the reign of Jahangir, his grandson, that Mughal paintings flourished.

Option 2, Akbar, is also incorrect. Although Akbar made significant contributions to the arts and patronized the development of Mughal painting, it was during Jahangir`s reign that the art form reached its peak.

Option 4, Shahjahan, is incorrect as well. Shahjahan, known for building the Taj Mahal, continued to patronize the arts, but it was Jahangir who was particularly known for his love for paintings and his support of Mughal artists.

In summary, option 3, Jahangir, is the correct answer as Mughal paintings reached their zenith during his reign.