Who was earlier known as Siddhartha?

The correct answer is Option (1) → Gautam Buddha

Siddhartha Gautama was born a prince of the Shakya clan at Lumbini, in present-day Nepal, around the 6th century BCE. He left home at 29 in search of the cause of suffering and, after attaining enlightenment at Bodh Gaya, came to be called the Buddha, “the enlightened one”.