How did advancements during the Gupta period transform mathematics

A.They invented algebra.
B.They created the concepts of square numbers and square roots.
C.They developed a decimal system with a numeral for zero.****
D.They made progress in metallurgy.

Under whose reign did the Gupta empire reach its greatest size?

A.Chandragupta Maurya
B.Chandra Gupta I
C.Samudra Gupta
D.Chandra Gupta II
Idk this one

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