Which of these is an example of an idiom?

dr. kings dream speech

explanation:

it was late in the day and hot, and after a long march and an afternoon of speeches about federal legislation, unemployment and racial and social justice, the rev. dr. martin luther king jr. finally stepped to the lectern, in front of the lincoln memorial, to address the crowd of 250,000 gathered on the national mall.

b

explanation:

your blank of voice often reflects your feelings emotion and thoughts

man i love you so much

have a good day

and add me as friend