Which European country acts as the guarantor for the Central Bank of West African States and the stability of the CFA franc currency?

Introduction / Context:
Many African countries use a common currency called the CFA franc, which is issued by the Central Bank of West African States. A key feature of this monetary arrangement is the formal guarantee provided by a European country, which supports convertibility and stability. Questions of this sort test knowledge of international monetary relationships, colonial history and modern economic cooperation between Europe and Africa.

Given Data / Assumptions:

• The question asks which European country is the guarantor for the Central Bank of West African States (BCEAO) and its currency.
• Options: France, United Kingdom, Germany and Switzerland.
• The context is the monetary union in West Africa that uses the CFA franc.

Concept / Approach:
The CFA franc currency zones were originally created in the colonial period, mainly linking French colonies in Africa to the French economy. After decolonisation, these arrangements evolved but still kept a connection with France. France provides a convertibility guarantee for the CFA franc, meaning the currency can be converted into the euro at a fixed rate under specific arrangements. Therefore, the European guarantor of the Central Bank of West African States is France, not any of the other listed countries.

Step-by-Step Solution:
Step 1: Identify that the Central Bank of West African States (BCEAO) serves francophone West African countries that use the CFA franc. Step 2: Recall that the CFA franc originated as a French colonial currency and still has a formal link with France. Step 3: Understand that France provides the main monetary guarantee for this currency arrangement, including a mechanism for convertibility into the euro. Step 4: Evaluate the options: the United Kingdom, Germany and Switzerland have their own separate monetary histories and do not guarantee the CFA franc. Step 5: Conclude that France is the correct European guarantor for the Central Bank of West African States.

Verification / Alternative check:
You can verify this by checking information on the CFA franc and the West African Monetary Union. Reputable economic references explain that France holds a significant share of the foreign exchange reserves and offers a guarantee arrangement through the French Treasury. This historical and institutional link is widely cited in books on African monetary unions and international economics, confirming that France, rather than another European power, is the guarantor.

Why Other Options Are Wrong:
United Kingdom: West African countries that use the CFA franc were previously French colonies, not British colonies, so the UK does not guarantee this currency.
Germany: Germany is an important member of the euro area but does not have a historical currency arrangement directly guaranteeing the CFA franc in West Africa.
Switzerland: Switzerland has its own national currency and a different financial relationship with the world; it does not play the formal guarantor role for the CFA franc zone.

Common Pitfalls:
A common mistake is to assume that because the CFA franc is now linked to the euro, the guarantor might be the euro area as a whole or Germany as the largest euro area economy. However, the legal and historical arrangement is specifically with the French government. Remembering the colonial background and the word "franc" naturally connects this currency and the Central Bank of West African States to France.

Final Answer:
The European country that guarantees the Central Bank of West African States and the CFA franc currency arrangement is France.