To find out how many years of Earth's history each yard line on a 100-yard football field represents, we can divide the total age of the Earth by the length of the football field.
The age of the Earth is approximately 4.6 billion years, which can be represented as:
4,600,000,000 years
The length of the football field is:
100 yards
Now, we divide the total number of years by the number of yards:
\[ \frac{4,600,000,000 \text{ years}}{100 \text{ yards}} = 46,000,000 \text{ years per yard} \]
Thus, each yard line on the football field represents 46,000,000 years of Earth's history.
The correct choice is:
46,000,000