[Solved] Which of the following emerged during the failure of centrally planned economic systems? A)black markets B)public markets C)free enterprise system D)market economies Colonoscope: A thin, flexible tube equipped with a camera and light at the end, used to examine the inside of the colon. Proctoscope: A medical instrument designed for the visual examination of the rectum. Valsalva Maneuver: A technique where one attempts to exhale forcefully with a closed mouth and pinched nose, used in medical examinations. Occult Blood: Blood present in such small quantities that it is not visible to the naked eye, often detected through specific tests.