The civilization's writing that has never been decoded is Harappan. Option B is correct.
Harappan writing has never been deciphered. The Indus Valley Civilization is also called the Harappan Civilization. Nowadays, the village of Harappa extends less than 1 km from the ancient site. Even though modern Harappa has a legacy railway station from the period of the British Raj, it is a small crossroads town of 15,000 people today.
The Indus script, also refered to as the Harappan script, is a corpus of symbols produced by the Indus Valley Civilisation during the Kot Diji and Mature Harappan periods between 3500 and 1900 BCE.