By how much has the average American lifespan increased since 1890?

The correct answer highlights that the average American lifespan has indeed increased by almost 30 years since 1890. In the late 19th century, the average lifespan in the United States was significantly lower due to factors such as high infant mortality rates, infectious diseases, and lack of modern healthcare. Over the decades, advancements in medical technology, improved public health measures, better nutrition, and increased access to healthcare have all contributed to a dramatic rise in life expectancy.

By 2023, the average lifespan has reached approximately 78-79 years, compared to about 48 years in 1890. This corresponds to an increase of nearly 30 years, illustrating the profound impact of these advancements on public health. The other answers suggest increases of 10, 20, or 40 years, which do not accurately reflect the historical data regarding lifespan changes over that period.