Why was Smith's speech important? A. Smith's speech was the first to publicly question McCarthy's accusations
B. Smith's speech was one of the earliest to refer to women as a vital voting bloc
C. Smith's speech was the first made by a woman senator
D. Smith's speech was the first to endorse McCarthy's approach to ensuring American safety

Im in between A and D but I think its D

Explanation:

She said "“Freedom of speech is not what it used to be in America,” she complained. “It has been so abused by some that it is not exercised by others.”She was a senators and usaually senators were only seen and not heard, As Senator Margaret Chase Smith grew increasingly angry with McCarthy’s attacks and his defamation of individuals she considered above suspicion. So she went to talk to Mr.President.

Its not B. "Smith's speech was one of the earliest to refer to women as a vital voting bloc" , because it didnt mention anything about women voting.

its not C "Smith's speech was the first made by a woman senator", because it mentions she was only ONE of the first senators to take such a stand.

Im sorry it took me long to answer I had to do some research on her to get the information.

hope this helped :)