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
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