Statistics question Math 302

Hi, could someone please help me figure out to approach this question? I don't know where to start.

The marketing manager of a large supermarket chain would like to use shelf space to predict the sales of pet food. For a random sample of 12 similar stores, she gathered the following information regarding the shelf space, in feet, devoted to pet food and the weekly sales in hundreds of dollars.
 
Store
1  2  3  4  5  6  7  8  9  10  11  12
Shelf Space
5  5  5  10 10 10 15 15 15 20 20 20
Weekly Sales
1.6  2.2  1.4  1.9  2.4  2.6  2.3  2.7  2.8  2.6  2.9  3.1
 
What is the estimated regression equation?
 A. y = 2.63 - 0.174x   
 B. y  = 2.63 + 0.724x   
 C. y = 1.45 + 0.074x   
 D. y = 1.45 + 0.724x