Answer: B
Step-by-step explanation:
When European explorers arrived in the New World they brought with them their technology and livestock that the Native Americans had never seen (like horses and guns).
The other options are wrong because:
Native Americans were often enslaved by European explorers and settlers (particularly by the Spanish and Portuguese in South and Central America).
Crops like corn were already present in the Americas and were a staple in Native American diets
They did not receive medicine that helped fight off disease, in fact diseases brought to the Americas by Europeans DECIMATED Native American populations.