<prompt> Cardiac muscle is able to function as a syncy-tium because of the structural presence ofBranching fibresIntercalated discProtoplasmic bridges between cellsGap-junctions  <response>: D i.e. Gap junction Cardiac muscle have characteristic intercalated discQ always at z line skeletal muscle have cross striation; and smooth muscles dont have both.Skeletal muscle has dark light bands and peripherally placed nucleusQ;where as cardiac muscle has intercalated disc centrally placed nucleusQEach cardiac muscle has a single nucleusQ. Cardiac muscle fiber branch interdigitateQ. Cardiac muscle function as a synctium because of presence of gap junctionQ. 