6. What is the correct order of plant evolution? (A) secondary cell wall → independent gametophytes → formation of protected embryo →double fertilization (B) secondary cell wall →multicellular gametophytes → double fertilization → formation of the protected embryo (C) independent gametophytes → secondary cell wall → formation of protected embryo →double fertilization (D)multicellulargameto phytes → secondary cell wall → double fertilization → formation of a protected embryo (E) multicellular gametophytes → formation of protected embryo→ secondary cell wall →double fertilization