Contractile vacuoles are organelles that maintain water balance by pumping excess water out of some single-celled pond organisms. In humans, the kidney is an organ chiefly involved in maintaining water balance. These facts best illustrate that
(1) tissues, organs, and organ systems work together to maintain homeostasis in all living things
(2) interference with nerve signals disrupts cellular communication and homeostasis within organisms
(3) a disruption in a body system may disrupt the homeostasis of a single-celled organism
(4) structures found in single-celled organisms can act in a manner similar to tissues and organs in multicellular organisms