Answer:
As well as giving us the concept of zero, Indian mathematicians made seminal contributions to the study of trigonometry, algebra, arithmetic and negative numbers among other areas. Perhaps most significantly, the decimal system that we still employ worldwide today was first seen in India
Explanation:
The expansion of railroads created more ways for things such as general goods to be shipped elsewhere to buyers or companies. (Hope this helps a bit, sorry for such a short answer.)
The correct answer is:
B) Satrapies.
Satrapies were the provinces of the Persian Empire, and they were governed by governors called satraps.
A explosion, which is unknown even to today what caused it to blow up.... but the US blamed it on the Spanish and declared war on Spain
hope this helps