The statement that accurately portrays what life was like for pioneers traveling west is: "Pioneers carried all their possessions on long and dangerous trails."
This reflects the reality that pioneers often had to bring their belongings with them and faced significant challenges and dangers during their journeys. The other options either misrepresent the nature of river travel, the safety of family travel, or the conditions of the trails, which were generally not well-maintained and could be quite difficult and perilous.