Why can the period from 1877 to 2010 be called the long american century

ok sorry the answer is a. by their religion

the dominoes began to fall. the surrender at appomattox took place a week later on april 9. while it was the most significant surrender to take place during the civil war, gen. robert e. lee, the confederacy's most respected commander, surrendered only his army of northern virginia to union gen. ulysses s. grant

explanation:

1.   île de la cité

2. 200 years

3. for the nave and choir

hope im right, havent learned about this in a year