Answer:
The exact answer is D. The number of laps Jessica increased her swim by each week (If you are taking Algebra 2 01.04)
Hope this helps!
Explanation:
She started week 0 with 8 laps. Week 1 she does 10 more. Each week she increases her laps by 10. W represents the week. 
Week Laps 
1 18 
2 28 
3 38 
4 48