Below, a statement has been divided into 5 parts. The one in bold is the fixed part, to which no changes can be made. Among the other parts (A), (B), (C) and (D), find the error-free part(s), and mark them as your answer. If there are no errors, then mark option (5), viz, No Error, as your answer.

In the history of the world we can (A) / distinguish several important formations / if the self-consciousness of Spirit (B) / in the course of it free self-development, (C) / each corresponding to a significant principle. (D)