Which common factor lead to the collapse of both the roman empire and the han dynasty a. as citizens turned more toward religious pursuits, their military forces suffered.
b. weak leaders used funds irresponsibly and could not gain the support of their subjects.
c. severe drought led to population decline and migration.
d. overfarming and urbanization depleted the natural resources of both regions.

the answer is: must pay taxes on profits

since it is considered as a part of your income, profits from investments is eligible for tax payment.

the tax from your investment could be influenced by how long you decided to sell it. united states promotes keeping your investment for long term period. so, the tax rate for investments that you sell in less than one year is typically higher compared to investments that you sell in more than one year period.

cultural/diplomatic relations. most medieval japanese   culture has chinese origins. writing, architecture etc.