The graph shows the radioactive decay of a bone that is found to contain 1/8 of the carbon-14 found in living animals today.

To determine the age of the bone based on the decay of carbon-14, we can use the fact that the half-life of carbon-14 is approximately 5,730 years.

1. **Starting amount**: Let's say a living organism has 100% of carbon-14.
2. **After 1 half-life (5,730 years)**: 50% remains.
3. **After 2 half-lives (11,460 years)**: 25% remains.
4. **After 3 half-lives (17,190 years)**: 12.5% remains.
5. **After 4 half-lives (22,920 years)**: 6.25% remains.

If the bone contains **1/8** (12.5%) of the original carbon-14, this corresponds to **3 half-lives**.

Calculating the total time from the number of half-lives:
- 3 half-lives × 5,730 years/half-life = 17,190 years.

Therefore, the approximate age of the bone is **17,190 years**, so the correct answer is **d. 17,190 years**.