The first commercial oil well in Nigeria was discovered in

Analyze the question: It asks when oil was first found in commercial quantity in Nigeria. This is a history-of-the-Nigerian-economy fact, so there is no calculation, only recall.

Explain the concept:

• Shell-BP (then the Shell D'Arcy Exploration Party) began exploring in Nigeria in 1937, and a licence covering the whole country was granted in 1938. This is why 1938 appears as an option, but it marks the start of exploration, not a discovery.
• In 1956, Shell-BP discovered oil in commercial quantity at Oloibiri in present-day Bayelsa State (then the Niger Delta region).
• Production and export began in 1958, when the first shipment left Nigeria. This is the other common trap option.
• 1961 is when the Bonny oil terminal was commissioned, and 1951 is not a major oil milestone.

Step-by-step solution:

1. The question asks about the discovery of the first commercial well, not when exploration began or when exporting started.
2. Exploration began in 1938, so A is eliminated.
3. Exports began in 1958, so D is eliminated.
4. The commercial discovery at Oloibiri was in 1956.

Answer: C. 1956.

Tip: Remember the sequence 38 → 56 → 58: exploration begins (1938), oil is found (1956), oil is exported (1958). Also associate Oloibiri with 1956, and note that Nigeria's first oil well there is often called "Oloibiri Well No. 1."