All i know is its for science 8 but dunno where it goes so i just selected one sub-subect at random

ryan wants to borrow a dvd from zack so ryan walks 12 blocks to zack’s house, picks up the dvd, and then walks 12 blocks back to his house. what was the total distance ryan traveled?
answers :
a.12 blocks
b.24 blocks
c.0 blocks

Although china’s total economic output, measured by gross domestic product (gdp), is third largest in the world, it is considered a developing nation. what is most likely the most important factor for this designation? a. china’s government spends money on things that do not benefit human development. b. china has a large population, so its gdp per person is only modest. c. china has a strong economy but weak literacy and school attendance rates. d. china’s high rates of disease offset the country's economic gains.