Nigeria shares its longest border with which West African country?

Analyze the question: It asks which neighbouring country shares the longest border with Nigeria. Note the phrase "West African country" and the options given.

Concept: Nigeria has four neighbours:

• Benin Republic (west): about 773 km
• Niger Republic (north): about 1,608 km
• Chad (northeast): about 87 km
• Cameroon (east): about 2,100 km

Ghana does not border Nigeria at all. Togo lies between Benin and Ghana.

Solution:

1. Rank the borders by length: Cameroon (about 2,100 km) > Niger (about 1,608 km) > Benin (about 773 km) > Chad (about 87 km).
2. Cameroon is the longest overall, but it is a Central African country and is not among the options.
3. The question asks for a West African country, so Cameroon is excluded. Among the options, Niger has the longest border.
4. Ghana is not a neighbour. Benin (773 km) and Chad (87 km) are both shorter than Niger's border.

Answer: Niger, which is option A.

Tip: Remember the order of Nigeria's borders as "Cameroon, Niger, Benin, Chad" (longest to shortest). When a question says "West African", drop Cameroon and Chad (Central Africa) and pick Niger. Also remember that Ghana is not a direct neighbour of Nigeria, a common trap in JAMB.