The correct answer is D. IGNORE ALL..
If a flagged word is spelled correctly, right click it and then click ignore all on the shortcut menu to instruct word not to flag future occurrences of the same word in this document.
Explanation;
It ignores it for the current session . Additionally, if a new session is created it shows it as an error and ignores that specific word from that specific document but show an error if the word is written again on the document