Refer the given flowchart of sewage treatment, accordingly match Column I with Column II and select the correct answer from the codes given below:
Column IColumn IIA.The stage in which physicaltreament of sewage is done(i)Anaerobic degestion of activatedsludge and production of biogasB.The stage in which biologicaltreatment of sewage is done(ii)Activated sludgeC.Name of the sediment in primary treatment(iii)Aeration tanksD.It is carried to aeration tanks fromprimary settling(iv)Primary effluentE.Name of the sediment in secondary treatment (v)Primary sludgeFSite of flocs growth(vi)Secondary treatmentGFunction of sludge digester(vii)Primary