Final answer:
In 1970, about 80% of American children lived with two parents, and the number decreased to roughly 60%-66% by 2000. The U.S. has a higher proportion of single-parent families compared to other industrialized countries, with the associated economic and social challenges.
Step-by-step explanation:
In 1970, approximately 80% of American children lived with two parents. By the year 2000, this number decreased, reflecting a shift in family structures over time. Although not specifically provided in the figures mentioned, analyzing the data and trends indicates that option (a) is the most plausible amongst the choices: In 1970, approximately 80% of American children lived with two parents, and in 2000, it decreased to about 60% to 66%, indicating a decline in traditional two-parent households over the 30-year span.
The proportion of single-parent families in America is indeed higher compared to other industrialized nations, which is reflected in the increased percentages of children living with only one parent. This change in family dynamics has significant implications for the economic and social welfare of children, as single-parent families often face more financial and educational challenges.