<h2>
The right answer is C.
</h2>
Note that in The Water Level vs Time graph, a <u>constant level</u> is represented by a line with slope=0 <u>(for example, segment 2)</u>, when the <u>level increases</u> (when the water is running in the tub) the slope is positive <u>(for example, segment 1) </u>and when the <u>level decreases</u> (when Alison turns the water off) the slope is negative (<u>for example, segment 5</u>).
Now, if we want to prove this, let’s read again the statement in option C, dividing each section (see figure attached):
1. Alison turns on the water and allows it to run in the tub for a few minutes (as the water runs in the tube, the water level<u> increases</u>)
2. She then turns the water off while she runs to answer the front door. (when this happens the <u>water level is constant</u>)
3. Alison comes back and allows water to run into the tub for a couple more minutes (again the <u>water level increases</u>)
4. She takes a short bath (the <u>water level is constant</u> because she turned the water off)
5. Alison allows the water to completely drain from the tub (When this happens, the <u>water level decreases</u>)