Let's break down the given problem.

Key Information:

• Initially, the ice sheet is 2 meters thick.
• After 3 weeks, the ice sheet's thickness has decreased to 1.25 meters.
• The thickness is decreasing at a constant rate, so we can model the relationship between thickness and time with a linear equation.

Define Variables:

• Let $y$ represent the thickness of the ice sheet (in meters).
• Let $x$ represent the number of weeks that have passed.

Steps to Approach:

1. Find the slope (rate of change):
   The thickness decreases from 2 meters to 1.25 meters in 3 weeks, so the slope $m$ is calculated by the formula: $m = \frac{\text{change in thickness}}{\text{change in time}} = \frac{1.25 - 2}{3 - 0} = \frac{-0.75}{3} = -0.25$ The slope $m = -0.25$, meaning the ice sheet's thickness decreases by 0.25 meters each week.

2. y-intercept:
   The initial thickness is 2 meters when $x = 0$, so the y-intercept is 2.

Graph Interpretation:

• Slope: The slope is known to be $-0.25$.
• y-intercept: The y-intercept is 2 because that is the starting thickness.

Conclusion:

The graph of the relationship is a line with a slope of $-0.25$ and a y-intercept of 2. Therefore, the answer is (B) Slope and y-intercept.

Would you like more details or further clarification?

Here are five questions to deepen understanding:

1. How would the graph change if the ice melted faster?
2. What does the x-intercept of this graph represent physically?
3. How would you find the x-intercept from the equation?
4. Could this scenario ever have a positive slope?
5. How would the equation change if the rate of melting was not constant?

Tip: In linear models, the y-intercept often represents the starting value, and the slope shows how the dependent variable changes per unit of the independent variable.