Which sentence uses dashes correctly?

a.
your brother—never the quiet type must have an opinion to share.

b.
the note—i don’t know who wrote it—says to move the car before it gets towed.

c.
by all accounts, he is—calm, funny, and quite an excellent teacher.

d.
the annual picnic is—always a popular event—we never miss it.

Read the opening lines of sojourner truth's speech "ain't i a woman? " well, children, where there is so much racket there must be something out of kilter. i think that 'twixt the negroes of the south and the women at the north, all talking about rights, the white men will be in a fix pretty soon. but what's all this here talking about? what tone do these lines convey?