Match List-I with List-II and select the correct answer from the options given below:

List-I	List-II
a. Soviet Union - German non-aggression pact	1. September, 1939
b. Germany invaded soviet union	2. March, 1939
c. Germany occupied Czechoslovakia	3. June, 1941
d. Germany invaded Poland	4. April, 1941

A. a-4, b-3, c-2, d-1

B. a-2, b-4, c-1, d-3

C. a-3, b-1, c-4, d-2

D. a-1, b-3, c-2, d-4

Answer: Option A