<prompt> The most appropriate circuit for ventilating a spontaneously breathing infant -Jackson Rees modification of Ayres T pieceMapleson A or Magills circuitMapleson C or waters to fro canisterBains circuit  <response>: Ayre;s T piece is used in infants. The patient inspires fresh gas from the reservoir tube,expires into the reservoir tube. Advantages are they are inexpensive,compact,no valves and low dead space 