About 75% of living matter is made up of which two essential chemicals?

An old movie poster used a quote "in space, no one can hear you scream! " why this is true or not true? a) the quote is incorrect, you can hear sound in outer space. b) sound cannot be polarized. so, you cannot hear sound in space. c) sound is an electromagnetic wave and needs no medium to travel through. eliminate d) sound needs a medium for the wave to vibrate and there is nothing in space to vibrate