Answer: D. $4,500
Step-by-step explanation:
According to the question, Diane had owned the shares for 4 years meaning it's in the long term bracket( mutual funds held for more than one year).
Hence, investment income received on long term shares of a mutual fund are called capital gains.
Also Diane belongs to the 35% marginal tax bracket, Hence, Diane's capital gains of $30,000 will be taxed at 15%. Because taxes on capital gains are dependent on the marginal tax bracket of the individual. Individuals in the 37% tax bracket, pays 20% tax on their capital gains.
Therefore, Diane tax will be:
15% of $30,000
0.15 × $30,000 = $4,500