Answer: A, The line starts at 9 and ends at 29
Answer:
1.04 inch
Step-by-step explanation:
Given: Old house has a basement stairways with 7.25 inch vertical riser and 7 inch horizontal treads.
Remember; horizontal treads is known as run in steps.
Now, calculating the slope of the stairways.
Formula: 
Rise= 7.25 inch
Run= 7 inch.
Subtituting the value in the formula
Slope=
(∵ Round to two decimal)
∴ Slope of stairways is 1.04.
I am almost positive that the answer could be 8 feet below sea level