Following are the figures showing germinal layers in organisms.Choose the correct answer w.r.t. figures (a) and (b).

Animals in which the cells are arranged in two embryonic layers, an external ectoderm and an internal endoderm, are called diploblastic animals. An undifferentiated layer, mesoglea, is present in between the ectoderm and the endoderm in diploblastic animals. E.g., coelenterates.Those animals in which the developing embryo has a third germinal layer, mesoderm, in between the ectoderm and endoderm, are called triploblastic animals. E.g., platyhelminths, chordates.