Final answer:
The steeper the slope, the faster the fire spreads uphill due to intensification of flames and wind influence.
Step-by-step explanation:
The question poses a scenario on the spread of fires on slopes. The correct answer is that B) The steeper the slope, the faster the fire spreads uphill. This is due to several reasons: the fire burns with more intensity charging uphill, especially when driven by wind, and topography plays a vital role in how a fire spreads.
The relation to a slope can be similarly understood as the steepness of a straight line graphically, where a steeper slope indicates more rapid changes vertically (altitude or fire spread rate), while a flatter slope suggests less rapid change.