Answer: (a)

Explanation:
Inference 1 can be drawn (Correct): The extensive recovery of individual spindle-whorls made of terracotta or precious materials inside common residential households, paired with the complete archaeological absence of mechanical, automated spinning wheels, directly implies that textiles were produced manually. This tells us that spinning was a time-consuming, highly laborious activity done by hand at the household level.

Inference 2 can be drawn (Correct): The discovery of highly standardized cubical chert weights and linear measuring scales featuring exact, mathematical graduations (such as the ivory scale found at Lothal or the shell scale from Mohenjo-daro) proves that the Harappans possessed advanced scientific and mathematical knowledge, specifically in binary and decimal configurations, to regulate their vast trading network.

Inference 3 cannot be drawn (Incorrect): Statement III describes large private residential units featuring their own enclosed courtyards, independent private wells, individual bathing platforms, and distinct private rooms. Rather than suggesting a common property system (public or shared communal property), these architectural setups strongly imply private ownership and structural socio-economic stratification among household units.