GENERAL KNOWLEDGE

Detailed explanation-1: -The correct option is B Artificial ecosystem.

Detailed explanation-2: -Rice-field is an artificial ecosystem because the fields are grown by men for agricultural needs. They do not occur naturally that is why it an artificial ecosystem.

Detailed explanation-3: -Ecosystem services provided by paddy fields include; groundwater recharge, production of non-rice foods, flood control, soil erosion and landslide prevention, climate-change mitigation, water purification, culture and landscape, and support of ecosystems and biodiversity.

Detailed explanation-4: -By practising the levelling of land biotic factors get destroyed. This can be retained by filling of paddy which represents the primary producers. Primary consumers are organisms that eat the primary producers and are usually herbivores.

Detailed explanation-5: -Crop fields are not like wild forest area, it is a piece of land which has to be converted and managed. The soil is prepared for sowing seeds, then irrigated and further also kept under observation for getting good yield of crops. Thus, crop field is an artificial ecosystem.