The correct option is B Both A and B
Ecological sanitation
For handling human excreta, a sustainable system was developed known as ecological sanitation or Ecosan, which uses dry composting toilets. With this composting method, human excreta can be recycled into a resource (as natural fertiliser), which reduces dependence on chemical fertilisers.
Municipal toilets
Municipal toilets are public toilets found in markets, railway stations, and other areas of the city. They are not sustainable systems of handling human excreta.
Final answer
(D) Both A and B