Jan is unmarried and has no children, but she provides all of the financial support for her mother, who lives in an apartment across town. Jan's mother qualifies as Jan's dependent. Which is the most advantageous filing status available to Jan?

HOH(head of household ) status

Explanation:

HOH(head of household ) status is the tax filling status that is provided to a person who persist qualities like unmarried status, must have at-least one qualifying dependents, receives payment more than half the cost of maintaining home  

According to the question,Jan has the freedom for claiming head of household status for herself as she is a unmarried woman who helps in maintenance of separate residence for her mother who is considered a qualifying dependent.

d. the polar jet stream   lies between the polar easterlies and trade winds should be your answer