Answer:
C. Slope and 
Step-by-step explanation:
We're missing the graph itself, but I can make an educated guess:
- Assuming x = volume and y = mass:

density = mass/volume
x = volume = run
y = mass = rise
mass/volume = rise/run = slope
The slope of the line (assuming the graph is purely linear) represents mass/volume, which is the formula for density.
I had to Google the density of silver itself. Do the math from the graph for a more appropriate answer, as the graph may be less scientifically precise.
8th grader here, what do you need help with?
Answer:
the "?" represents the number 175
Step-by-step explanation:
126/18=7
so, you would multiply the 25 by 7 to get 175
hope this helps!