Which sentence contains an error in the use of end marks or commas?

A.Miss K.C. Fairchild will lead the band in a Sousa march.
B. Mom, what does B.C. mean?
C.Dr. and Mrs. Majeck will attend the party on March,12,2007.
D. Address inquiries to Ella Adams, 315 Elm St., St. Petersburg, FL 33707
My answer for this Q is B plz check ^^;

Nope.

... end marks or commas?

No, B is correctly done.

Oh yeah, I forgot to add another Q ^^;

A.Walker, an expert on radar, will be here for about 90 minutes.
B.After his tour of duty ends he intends to work for Science Pathways Corp.
C.I met him last summer in Pensacola, and we have kept in touch by writing letters.
D.Lt.Walker will be coming on Thursday to tell us how radar works.
My answer for this Q is B as well :)

B is right for your last question.

I have a feeling its D for the first Q ^^;

"have a feeling" ??? Why aren't you studying?

http://grammar.ccc.commnet.edu/grammar/commas.htm
Go through the different comma uses here. Study them.

No guessing, no feeling ... learn these things!

what I meant that I had a feeling that it was a D because on 315 Elm St it shows that it has a period and then a comma wouldn't that be incorrect?

No. "St." is an abbreviation for "Street" and has a period. The period here indicates an abbreviation, not the end of a sentence.

oh sorry ^^;

To determine which sentence contains an error in the use of end marks or commas, we need to examine each sentence closely. Let's go through each option:

A. "Miss K.C. Fairchild will lead the band in a Sousa march."
In this sentence, there are no errors in the use of end marks or commas. It is grammatically correct, as it states that Miss K.C. Fairchild will lead the band in a Sousa march.

B. "Mom, what does B.C. mean?"
This sentence is correctly punctuated. The comma after "Mom" is used to set off the vocative (direct address), which is a proper use of commas. The question mark at the end indicates it is an interrogative sentence. Therefore, option B is not the incorrect sentence.

C. "Dr. and Mrs. Majeck will attend the party on March,12,2007."
In this sentence, there is an error in the use of commas. When indicating a date, there should be no comma between the month and the day. The correct form would be "March 12, 2007." Therefore, option C contains the error.

D. "Address inquiries to Ella Adams, 315 Elm St., St. Petersburg, FL 33707."
This sentence is correctly punctuated. The commas are used to separate the address elements and the periods at the end indicate the abbreviations in use. Therefore, option D is not the incorrect sentence.

Therefore, the correct answer is C.