Which of the following was an accomplishment of metallurgists during the gupta empire?

a the development of the iron plow

b the invention of seismographs made from bronze

c the development of the process of gold-plating

d the creation of a rust-resistant iron pillar

The correct answer is "D".

The Gupta Empire was a dynasty that extended its rule across northern, central, and part of Southern India between CE 320 and CE 550.

During this period, metallurgy was already at a very developed stage and forged iron became a commodity throughout the empire. As it became a very valuable article for trade.