Suppose John Is Planning to Join a Sports Club

Suppose John is planning to join a sports club. Membership in the club will allow John to swim at the pool for half price. Normally swimming for an hour would cost $10. If John has an income of $1000, the club membership fee is $100, and we plot the number of visits to the pool on the horizontal axis and a composite "other goods" which have a price of $1 on the vertical axis, the equation of John's budget line after joining the club, where the composite good, y, is on the vertical axis and pool visits, x, are measured on the horizontal axis is

A) y = 900 - 5x
B) y = 1000 - 5x
C) y = 1000 - 10x
D) y = 900 - 10x