Concept:Invisible trade refers to the buying and selling of services that cannot be seen or touched, rather than physical goods.
Explanation:An invisible item of trade is a service that has economic value but no physical form.
Examples include shipping, banking, insurance, tourism, and consultancy services.
Oil is a tangible commodity that is extracted, stored, and sold as a physical product.
Machinery is a manufactured good that can be seen, handled, and inspected.
Textile is a physical fabric material that can be measured and weighed.
These three options are all classified as visible trade items.
Shipping is the service of transporting goods and passengers from one place to another.
It does not involve the exchange of a tangible commodity itself.
Instead, shipping provides a service for which payment is made.
Therefore, among the options given, shipping is the only invisible item of trade.
Answer:B. Shipping