I'm not sure exactly what unit you're referring to, but three of the main factors that affect oil prices today would be natural disasters, futures trading, and global demand.
The answer is is c thats the correct answer
Improvements in transportation led to : A. Lower shipping costs for goods
Improvement in transportation usually followed by increased in efficiency, whether it's a larger space to deliver goods or fewer fuel needed to reach the destination. Both will lead to lower shipping cost
hope this helps
