The correct answer is Option 1 - Ashoka. The beautiful wooden ratlings in the Sanchi stupa were indeed made during his reign.

Ratlings are small decorative wooden discs that are used in the construction of Buddhist stupas. They are arranged in a pattern on the outer edges of the stupa. The Sanchi stupa, located in present-day Madhya Pradesh, India, is one of the oldest and most important Buddhist monuments in the country.

Ashoka, also known as Ashoka the Great, was an Indian emperor of the Maurya dynasty who ruled from 268 to 232 BCE. He played a significant role in spreading Buddhism across India and building numerous stupas and monasteries. It is believed that the wooden ratlings in the Sanchi stupa were created during his reign as a form of ornamentation and symbolism.

While the Satavahanas, Guptas, and Harsha were all important historical figures in ancient India, there is no evidence or historical records suggesting their involvement in the creation of the wooden ratlings in the Sanchi stupa. Therefore, the correct answer is indeed Option 1 - Ashoka.