A is probably the most correct answer out of all of these.
While medieval art typically shows blank faced people stabbing each other, (or extremely ugly babies) many features of renaissance to suggest movement, whether by cloth falling or rippling or by certain stances.
And C well, renaissance art vs medieval is no contest in color...
Medieval art is more typically concerned with religion due to the overwhelming power of the church at the time; not to say it wasn't crazy powerful during the renaissance period, but Renaissance art typically focused on humanism more than it's religious undertones. This is most likely due to basic evolution in society that was occurring.