Explanation:

- Option 1: Rudradaman

- Rudradaman was a prominent Western Kshatrapa ruler. He is known for his patronage of arts and Sanskrit literature but did not start the Shaka Era.

- Option 2: Gondaphernes

- Gondaphernes was an Indo-Parthian king. He is mentioned in historical texts for ruling parts of present-day Afghanistan and Pakistan. He did not start the Shaka Era.

- Option 3: Vikramaditya

- Vikramaditya is a legendary king, often associated with the Vikram Samvat calendar, which begins in 57 BC, not the Shaka Era.

- Option 4: Kanishka

- Kanishka, the famous Kushan emperor, is traditionally credited with starting the Shaka Era in 78 AD.

Correct Answer