Chapter 11 described a study that investigated the stability of advance directives. Researchers ...

Chapter 11 described a study that investigated the stability of advance directives. Researchers asked study participants to state their preferences for various life-sustaining treatments in different medical scenarios; they had these participants state their preferences twice (immediately and after varying delays). What did they generally find?
 
  A. Participants' preferences were very stable over time.
  B. Approximately one-third of participants stated treatment preferences changed over time.
  C. Nearly half of participants stated treatment preferences changed over time.
  D. Almost all of participants stated treatment preferences changed over time.