Which of the following was not known to Indus Valley people?

Q. Which of the following was not known to Indus Valley people?
(a) Silver
(b) Copper
(c) Iron
(d) Bronze
Ans: (c) Iron

Q. Which of the following was not known to Indus Valley people?
(a) Silver
(b) Copper
(c) Iron
(d) Bronze
Ans: (c) Iron