Which harvest festival is famously celebrated in Assam?

Correct option is C

The answer is (c).
 The entire state of Assam celebrates Bohag Bihu with lots of excitement every year in April. It marks the start of the Assamese calendar year. This harvest festival in India is also known as Magh Bihu.
 Lohri is a popular winter Punjabi folk festival celebrated primarily in Northern India.
 Makar Sankranti, also referred to as Uttarayana, Makar, or simply Sankranti, is a Hindu observance and a festival. Usually falling on the date of January 15 annually, this occasion marks the transition of the sun from the zodiac of Sagittarius to Capricorn.
 Onam is an annual Indian harvest festival celebrated mainly in Kerala.