Similar characteristics between animals that are the result of common ancestry（共同祖先） are called ( ). A: analogies B: clades C: homologies D: phylogenies E: hierarchies

If the cladogram is obtained by examining common homologies, which of the following contains orders that would be in one clade? A: Orectolobiformes and Carcharhiniformes B: Heterodontiformes and Squaliformes C: Rajiformes and Rhynchobatiformes D: Chimaeriformes and Echinorhiniformes