To calculate the percent increase, you can use the following formula:
\[ \text{Percent Increase} = \frac{\text{New Value} - \text{Old Value}}{\text{Old Value}} \times 100 \]
In this case, the old value is $100,000 and the new value is $115,000.
\[ \text{Percent Increase} = \frac{115,000 - 100,000}{100,000} \times 100 \]
This simplifies to:
\[ \text{Percent Increase} = \frac{15,000}{100,000} \times 100 \] \[ \text{Percent Increase} = 0.15 \times 100 \] \[ \text{Percent Increase} = 15% \]
So the percent increase is 15%, which corresponds to option B.