In the period after circa 1450, trade along the routes shown on the map declined in large part because of the____

a. decrease in the demand for African manufactured goods in Europe

b. collapse of European economies in the wake of the Bubonic plague

c. disruption caused by the adoption of new gunpowder weapons

d. increase of maritime trade along the African coast

The trade route before 1450 was the Silk Road.
The Silk Route is one of the oldest trade routes that link China to Europe.
The Silk Route was named silk as it was one of the commodities introduced in Europe and sold.
The Silk was one of the expensive products and symbol of status.
An excess of the sea route (Indian Ocean trade) brought an end to the dominance of the Silk Road.
The Silk route often saw clashes, robbery and unrest between Christians and Muslims.
A new sea route was found with Vasco da Gama on his way to India and the Far East in the 15th century.

Therefore we can conclude that there was a shift in the trade route from land to ocean.

Thus option D. is the correct answer.

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