the slope represents:
[tex]\frac{change\text{ }in\text{ y variable}}{change\text{ }in\text{ x variable}}[/tex]in this case
[tex]\frac{1.9}{1}=1.9\text{ }[/tex]this is, The boiling point increases by 1.9° F for every inch of mercury the pressure increases, therefore:
answer: A.
