The correct option is (a).
Explanation
The Harappan Civilization developed a highly standardized and precise system of weights and measures to regulate exchanges and trade. These weights were uniform across the vast geographical extent of the civilization, reflecting a centralized or mutually agreed-upon system of commerce.
Statement-wise Analysis:
- Statement 1 is Correct: The weights were usually made of a stone called chert (a type of sedimentary rock). This material was chosen for its durability and ability to be shaped precisely.
- Statement 2 is Incorrect: The standard Harappan weights were generally cubical in shape, not spherical. They were simple, geometric cubes without any handles.
- Statement 3 is Incorrect: Unlike modern weights, these stone weights usually had no markings or inscriptions indicating their value. The system relied on standardized sizes following a specific weight ratio (binary system in lower denominations and decimal in higher denominations).
Key Takeaway:
Harappan weights were characterized by their standardization; they were typically made of chert, were cubical in shape, and were unmarked.