What best describes what happens to energy and molecules in a stable ecosystem

 Which statement best describes what happens to energy and
molecules in a stable ecosystem?
(1) Both energy and molecules are recycled in an ecosystem.
(2) Neither energy nor molecules are recycled in an ecosystem.
(3) Energy is recycled and molecules are continuously added
to the ecosystem.
(4) Energy is continuously added to the ecosystem and
molecules are recycled. Update: I kno what the answers is (4) but i dont get it
haah and this is a ap bio person talking

hey its hard when you go from difficult questions

Were is the question