HELP, GIVING BRAINLIEST!
What, in addition to geographic boundaries, might have kept the people of the Huang River civilization from traveling to far-distant regions?

A. They feared that their bronze weapons would be no match for the iron weapons of ancient Egypt.
B. They could get everything locally that they needed to survive and grow.
C. They had learned about the other river valley civilizations but feared contact would bring invasion.
D. They had not yet developed a system of money based on coins.

they had not yet developed a system of money based on coins

Explanation:

D

B. They could get everything locally that they needed to survive and grow.

Explanation:

i believe the answer is a

lee and grant, both of whom held the highest rank in their respective armies, had known each other slightly during the mexican-american war (1846-48) and began their dialogue by exchanging awkward personal inquiries. characteristically, grant had arrived in his mud-splattered field uniform while lee had turned out in full dress attire, complete with sash and sword.

explanation: