From the following graph code ,which code snippet will return the no.of flight routes?
sc.parallelize (Array(1L, ("SFO")), (2L, ("ORD")), (3L,("DFW"))))
val routes =sc.parallelize
val nowhere = "nowhere"
val graph = Graph(airports,routes,nowhere)
a)val numroutes = graph.numVertices
b)val numroutes = graph.numEdges
c)val numroutes = graph.nowhere
d)val numroutes = graph routes