The author explains that a nominal constitution may contain high principles but is not actually reflected in political reality.
He contrasts normative constitutions (fully enforced) with nominal constitutions (not enforced in practice).
In this context, “normal” is synonymous with “nominal,” meaning the constitution is largely a façade while real political power is guided by other rules.
Option (a) is incorrect — a normal constitution could be written or unwritten.
Option (b) is incorrect — lofty ideals are not unique to normal constitutions; they also appear in normative constitutions but with enforcement.
Option (c) is incorrect — length is unrelated to whether a constitution is enforced or not.
Thus, (d) is correct.