A type of constitution suitable for the governance of a federal state is a

Step 1: Analyze the question The question asks which type of constitution best suits a federal state, one where power is shared between a central government and component units (like Nigeria's federal government and the 36 states).

Step 2: Explain the concept

• A flexible constitution can be amended easily, often by the ordinary legislative process (e.g., the UK's).
• A rigid constitution requires a special, difficult procedure to amend, such as a two-thirds or three-fourths majority in the legislature, plus approval by a number of state legislatures or a referendum (e.g., Nigeria's 1999 Constitution and the USA's).
• Republican and parliamentary describe the form of government or executive arrangement, not how easily the constitution is amended. A federation can be either, so these don't specifically define what suits federalism.

Step 3: Apply to federalism In a federation, the constitution is the supreme document that divides powers between the central and state governments. If it were flexible, the central government (or a simple majority in the legislature) could change that division at will and take away the powers of the states. A rigid constitution protects the autonomy of the component units, because no change can be made without wide consensus, including the states themselves. That is why Nigeria's constitution requires state Houses of Assembly to approve amendments (at least two-thirds of them).

Step 4: Answer The correct option is B. rigid constitution.

Tip: Think "Federal = Fixed." Federalism needs a constitution that is hard to change, so it protects the shared power arrangement. Unitary states can more easily get by with flexible constitutions.