Which statements must be true? Select each correct answer. ST=2ON OM¯¯¯¯¯¯∥TU¯¯¯¯¯ ON=12SU NO=NM MN¯¯¯¯¯¯¯∥SU¯¯¯¯¯ The figure shows what appears to be acute triangle S T U. Point M is on side S T. Single tick marks pass through segments S M and M T. Point N is on side T U. Double tick marks pass through segments T N and N U. Point O is on side U S. Triple tick marks pass through segments U O and O S. Segments M N, N O, and O M are drawn.