The answer is C
Reasoning: I did it already lol
The majort cause of the European exploration was the search for spices.
Back then, spices such as chili and pepper was one of the most profitable commodity in European Trades.
The exploration was being done in order to find other spices resources that the merchant guilds could buy with cheaper price.
Of that list, the following occurred during President Truman's administration: the Marshall Plan, the creation of NATO, and the creation of Pakistan. Of the remaining, the Manhattan Project began under President Franklin Roosevelt's term, but finished under Truman's following FDR's death in office. The Cuban Revolution and the Suez Crisis occurred under President Eisenhower's administration.
To mass produce instead of writing each Print one-by-one.
*Example: Stamps are use to mass produce Print on envelopes, papers, etc.*