I think the answer is D:all of the above.
Answer:
Virus's,
there would be stealing too
Explanation: The silk road was one of the largest roads built for trading across countries and as they traded the virus's were spreading there was also I really bad type of virus's but I forgot the name. I think you should research about it to get more points and i think this is history related not geography. Enjoy.
Just look up the illness you want information about in your search engine (for example, Google, bing, or yahoo) and find a website that ends in .org, .edu, or .gov. those are the most trustworthy websites to find good information. websites that end in .com are mostly not trustworthy because anyone can have a website that ends in .com and could tell you false information. websites ending .edu are owned by colleges and have better information for you.
