The correct option is 1 only
Explanation
The steatite seals of the Indus Valley Civilization are a primary source of information regarding Harappan culture, trade, and religion. These seals typically feature an animal motif surmounted by a line of the undeciphered Indus script. The "Unicorn" is the most prominent among these motifs.
Statement 1 is Correct: The creature is depicted with a single, long, sinuous horn curving back from its head. While some scholars suggest it may represent a bull in profile (where one horn obscures the other), it is conventionally categorized and described in archaeological literature as a "Unicorn" or a one-horned animal.
Statement 2 is Incorrect: The Unicorn is widely regarded as a mythical or composite animal, not a realistic rhinoceros. The Harappans were familiar with the Indian Rhinoceros and depicted it realistically on other seals, clearly showing its rugged, folded skin and snout-based horn. The Unicorn, conversely, has a smooth body resembling an ox or antelope.
Statement 3 is Incorrect: The Unicorn is not rare; it is the most common animal motif found on Harappan seals. It appears on the majority of seals discovered at major urban centers like Mohenjo-daro and Harappa.
Key Takeaway: The "Unicorn" is the most frequently occurring motif on Indus Valley seals, representing a mythical one-horned creature that is distinct from the realistic depictions of the rhinoceros.