ATM reference model comprises of three layersPhysical Layer In this layer, the cells are converted into bitstreams and transmitted over the physical medium. This layer has two sub-layers: PMD sublayer (Physical Medium Dependent) and TC (Transmission Convergence) sublayer.ATM Layer It accepts the 48-byte segments from the upper layer, adds a 5-byte header to each segment, and converts into 53-byte cells. This layer is responsible for routing of each cell, traffic management, multiplexing and switching.ATM Adaptation Layer It provides facilities to the existing packet-switched networks to connect to the ATM network and use its services. It accepts the data and converts them into fixed-sized segments. This layer has two sub-layers ? Convergence sub-layer and Segmentation and Reassembly sub-layer.ATM Applications:ATM WANsMultimedia virtual private networksFrame relay backboneResidential broadband networksCarrier infrastructure for telephone and private line networks Therefore All of the options is the answer