Will someone me answer this

luca and william are playing a video game and they have scored a total of 20,000 points. luca scored 4,000 more points than william. if you let l= the number of points that luca scored, and w= the number of points that william scored, then the problem can be represented by the system:

l+w=20,000 and l=w+4,000

graph the system. how many points did each boy score?

my possible answers are:
a. william = 8,000 and luca = 12,000
b. william = 12,000 and luca = 8,000

d. william = 4,000 and luca = 16,000