<prompt> Twin Peak sign is characteristic ofDichorionic DiamnioticMonochorionic DiamnioticMonochorionic MonoamnioticConjoined twins  <response>: Determination of ZygositySonographic Determination:ChorionicityDividing inter-twin membrane thicknessSignDichorionicity 2mmTwin peak sign or Lambda signMonochorionicity 2mmT signReference: Williams Obstetrics; 25th edition; Chapter 45; Multifetal pregnancy 