Carlos has a box containing bags of potato chips and pretzels. He told Sarah that the probability that she randomly selects a bag of potato chips is 1/2. Which of the following can be the contents of the box?
A: 5 bags of potato chips and 10 bags of pretzels
B: 4 bags of potato chips and 8 bags of pretzels
C: 8 bags of potato chips and 8 bags of pretzels
D: 10 bags of potato chips and 5 bags of pretzels