A writer has drafted four sentences for a paragraph about animal shelter volunteers. Sentences: (1) The animal shelter should invite more student volunteers on weekends. (2) A weekend schedule would also let students serve when they are not in class. (3) Extra volunteers would free staff to give animals more exercise and attention. (4) On Saturdays, staff members spend much of the morning cleaning cages before they can walk the dogs. Which sequence most effectively connects the evidence to the writer's point about animal shelter volunteers?