Final answer:
The percentage of children living in the United States who live in poverty is closest to option b. 20%, based on recent years' poverty rates and the understanding that no less than 11% of the total population has been under the poverty line since the 1960s.
Step-by-step explanation:
The percentage of all children living in poverty in the United States can be deduced from the general poverty rates over time. According to the historical data presented, the poverty rate has fluctuated over the decades but has not been less than 11% of the U.S. population since the 1960s. It peaked at 15.9% in 2011 and then dropped to 14.5% in 2013. Given these statistics, the closest answer to the current percentage of children living in poverty would likely be around or slightly higher than the general poverty rate percentages presented.
However, it is crucial to consider that poverty rates for different groups can vary significantly. According to the provided data, poverty rates are comparatively higher for certain demographics, such as Hispanics and African Americans, than for whites. Hence, without more recent and specific data for children's poverty rate, we can deduce that the percentage of all children living in poverty in the United States is most closely aligned with option b. 20%.