B. 3 to 5 & D. 7 to 12. because unchanging, in this case, means not moving.(or the flat lines)
Answer:

Step-by-step explanation:
the slope is the change in y over the change in x
From the points given, your y's are 10 and 1.
From the points given, your x's are 7 and 2. To find the changes subtract them.
= 