A temperature of -15°F is how many degrees below zero?

To determine how many degrees below zero a temperature of -15°F is, simply look at the difference from the zero point on the Fahrenheit scale. When temperatures are expressed in negative values, the magnitude of the negative number indicates how far below zero it is measured.

In this case, -15°F is exactly 15 degrees below the zero mark. It is important to recognize that a negative temperature inherently denotes a distance below zero; thus, -15°F correlates directly to being 15°F under that baseline.

This understanding of temperature measurement helps clarify why this outcome is accurate, while the other choices represent incorrect interpretations of the distance from zero in the context of negative temperatures.