Could you explain why the correct answer is C and not B or D (I understand why A is wrong) ? Thank you! The legless condition that is observed in several groups of extant reptiles is the result of __________. (a) their common ancestor having been legless. (b) a shared adaptation to an arboreal (living in trees) lifestyle. (c) several instances of the legless condition arising independently of each other. (d) individual lizards adapting to a fossorial (living in burrows) lifestyle during their lifetimes .