Which of the following is not a main source of a constitution?

A.

Judicial precedents

B.

Legislative decisions

C.

Previous constitutions

D.

Public deliberations

Correct answer is D

Following are some of the sources peculiar with Nigerian constitution.
- Acts of Parliament 
- military decrees and the executive order.
- Qur'an, as in sharia law which is obtainable in most part of the northern Nigeria.
- Judicial precedents and landmark judgement.