They are sources that you can find the date, author, and have real facts and not just made up. Like if you went to the IRS website then that is a credible source for tax where as going to Wiki they are not credible because anybody can go there
"Are you sure you left it on the table?" asked Roberto. is the only correctly punctuated sentence here.
the first sentence requires a COMMA inside the quotations, rather than a period. "Judy said" is attached to the quote, because the quote is judy's words. you keep them together, rather than making them two separate sentences.
the third sentence is missing a comma as well. "oh no," sarah said... is the correct way to write it, with a comma after "no."
the fourth sentence is wrong for several reasons. your end punctuation goes inside your parentheses, and this sentence put the exclamation point after. "She laughed" additionally requires a period to end the sentence, stating that she laughed, then offering her dialogue. alternatively, you could place a comma after "laughed" and accept that for the verb leading into the quote.
I would narrow it down between A and C, but i think the answer is C.
