Difference between "disband" and "disperse"

Question

The police disbanded/dispersed the mob.

According to my textbook dispersed is correct.

I wanna know why disbanded is wrong or is it that dispersed is more appropriate? If so, then why? As disbanded also means the same - cause to break up.

Answer 1

American Heritage Dictionary "disband"
v.tr.
To dissolve the organization of (a corporation, for example).

v.intr.

1. To cease to function as an organization; break up.
2. To separate and move in different directions; disperse.

As you can see from the definitions, disband usually means to break up something that's organized to work together. Only the intransitive meaning overlaps with disperse.

A mob is not an organized thing, so disperse is the better choice in your example.