what are do you want from me i don't even know my bad
It is not A or C, and D isn't specific enough (over what amount of time? is it flying up? down? It is going forward at the same height?) The most likely thing to stay consistent is the cost of fabric and it's length.
Say 1 foot of fabric is $3 (assuming there's no discount for additional feet, but math isn't that consistent with actual store sales), then 2 is $6, and 3 is $9. That is a constant rate of change.
Think of a number line
You have -6 and -9
Jump 9 up the number line
Your answer is 3
The required equation is:

Step-by-step explanation:
Given
Let a be Anne's Age
and
b be Betty's age
Now we will onvert the given word problem in the form of equation step by step
"twice Betty's age." will be represented by 
Then
"3 years younger than twice Betty's age." will be represented as: 
Now
"Betty's sister, Anne, is 3 years younger than twice Betty's age."

Hence,
The required equation is:

Keywords: Word problems, linear equation in two variables
Learn more about linear equation in two variables at:
#LearnwithBrainly
its line a
Step-by-step explanation: