Assertion: The world trade pattern underwent a drastic change during the second half of the twentieth century.
Reasoning: Europe lost its colonies while India, China and other developing countries started competing with developed countries in the second half of 20th Century.

Both Assertion (A) and reasoning (R) are correct and R is the correct explanation of A.

The world trade pattern underwent a drastic change during the second half of the twentieth century. Europe lost its colonies while India, China and other developing countries started competing with developed countries. The nature of the goods traded has also changed.