Tom invests $15,000 in stocks, and the value increases by 8% annually. After three years, what will be approximately the value of his investment?

To calculate the value of Tom's investment after three years with an annual increase of 8%, we can use the formula for compound interest:

\[
A = P(1 + r)^n
\]

where:
- \( A \) is the amount of money accumulated after n years, including interest.
- \( P \) is the principal amount (the initial amount of money, which is $15,000).
- \( r \) is the annual interest rate (in decimal form, which is 0.08 for 8%).
- \( n \) is the number of years the money is invested or borrowed (which is 3 years).

Substituting the values into the formula, we have:

\[
A = 15000(1 + 0.08)^3
\]

Calculating that step-by-step:

1. Calculate \( 1 + 0.08 = 1.08 \)
2. Raise \( 1.08 \) to the power of \( 3 \):

\[
1.08^3 \approx 1.259712
\]

3. Multiply this result by the principal:

\[
A \approx 15000 \times 1.259712 \approx 18895.68
\]

Thus, after three years, the value of Tom's investment will be approximately $18,896.

Now, looking at the answer choices:
A. $15,000
B. $20,000
C. $25,000
D. $30,000

The closest answer to $18,896 is **B. $20,000**.