$\begin {array} {1 1} (A)\;The\: sum\: of\: any\: 2 \: natural \: numbers \: is \: even\: or\: odd. \\ (B)\;Students\: can\: take\: science\: or\: arts\: as\: their\: combination. \\ (C)\;Sun\: rises\: or\: moon\: sets. \\ (D)\;\sqrt 7\: (square\: root\: of\: 7)\: is\: rational\: or\: irrational. \end {array}$