Based on a 20-year-old student David's income situation, what can be concluded about his tax obligation?

The conclusion that David is exempt from taxes due to low total income is reasonable given his situation as a 20-year-old student. In the United States, individuals with very low income may fall below the minimum threshold required to owe federal income taxes. This threshold is defined by the IRS and varies based on factors such as filing status, age, and whether the individual is claimed as a dependent.

If David's income is particularly low and does not exceed these thresholds, he would indeed not have to pay income tax. It’s also important to note that many students may have part-time jobs or earn income that, when totaled, may not require them to file taxes.

The other choices are based on assumptions that do not necessarily apply to David's situation. While he may have some income, it does not automatically mean he owes taxes on all of it, that he must file regardless of income, or that he has investment income to report. Tax obligations hinge largely on total earnings and specific tax regulations that take into account various income types and personal circumstances.