Which of the following sentences is punctuated correctly?
AWhen I went into the store I saw the display right before it tumbled over.
BWhen I went into the store, I saw the display, right before it tumbled over.
CWhen I went into the store, I saw the display right before it tumbled over.
AWhen I went into the store I saw the display right before it tumbled over.
BWhen I went into the store, I saw the display, right before it tumbled over.
CWhen I went into the store, I saw the display right before it tumbled over.