When a student combed his dry hair for a long time, his hair began to stand up. which of these has most likely happened?

B)The comb and hair have become charged with opposite charges

Explanation:

When the comb was rubbed against dry hair, electrons moved from the hair to the comb. While the hair became positively charged, the comb became negatively charged by acquiring an excess static charge. In other words, the comb and hair have become charged with opposite charges.

1, 3, 4, and 5.