Final answer:
Silver (Option C) was the least likely to have been traded from western Africa to the east along the trans-Saharan trade route, as West Africa was known for trading gold and salt, not silver.
Step-by-step explanation:
From the 1000's CE through the 1400s CE, the good least likely to have traveled out of western Africa towards the east along the trans-Saharan trade route would have been silver (Option C). Western Africa was not known for its silver mines during this period. Instead, the two principal goods that the medieval empires of West Africa were renowned for were gold and salt, which were widely traded across the Sahara into the Middle East and Europe. Additionally, other commodities such as slaves, ivory, and copper also made their way across the Sahara.
Silver does not appear in accounts as a substantial export of West Africa during the medieval period. Instead, it was gold that was particularly abundant in West Africa, especially in the region of present-day Ghana, and was sought after by many across and beyond the African continent. Salt was equally valuable and was mined from places like Taghaza and traded for its essential uses, such as preserving food. Slaves were also a part of the goods traded on these routes, as they were transported and exchanged for a variety of products in other regions.