I prefer the second option - their advantages are simplicity and cheapness.

The government's major __________ has not only included legal, economic, and political gains but also changed the ways in which people live, dress, dream of their future and make a living.

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions. 

When there are diametrically opposing views on a big issue that concerns millions of people, doing comprehensible research just makes sense. 

Someone has just arrived, _______?