I am confused on question #20 in the back of the study guide.  It reads as follows:

Sally has a Personal Auto Policy with basic PIP and $1,000 Med Pay.  She takes her friend Beckie with her on vacation to Texas.  Sally drives her own car. In Texas, a drunk runs a light and hits Sally and Beckie.  Both are hurt.  Sally has $4,000 in medical bills and Beckie has $5,000 in medical bills.  What will Sally's policy pay in total from Med Pay and PIP?

The answer is $5,000.  Can you explain why it's only $5,000?  What happens to Sally's claim?