The most distinctive artifacts of the Harappan Civilization are presented as options in the question. Let`s dissect each option for a better understanding.

Option 1 states that the most distinctive artifact is a steatite seal. Steatite seals are indeed one of the most significant artifacts of the Harappan Civilization. These seals were often intricately carved with various symbols and animal motifs. They were used for various purposes, including trade and administrative activities.

Option 2 states that the most distinctive artifacts are bricks of a standardized ratio. This statement is incorrect. While standardized bricks were used in construction during the Harappan Civilization, they are not the most distinctive artifacts.

Option 3 states that the most distinctive artifacts are gold bangles and a silver spittoon. This statement is also incorrect. While gold bangles have been found in Harappan sites, they are not the most distinctive artifacts. Silver spittoons, on the other hand, were not associated with the Harappan Civilization.

Option 4 states that the most distinctive artifacts are a steatite seal, bricks of a standardized ratio, and gold bangles. This statement is partially correct. While the steatite seals and standardized bricks are indeed distinctive artifacts, gold bangles are not the most distinctive