Which of the following is likely to make petroleum drilling unimportant?

Analyze the question: The question asks which factor would make petroleum drilling unimportant (that is, not worth doing). So we are looking for a factor that works against drilling, not one that supports it.

Explain the concept: Petroleum drilling depends on several things:

• Resource availability: there must be oil in the ground in commercially viable quantities.
• Capital: drilling and offshore platforms are very expensive.
• Skilled labour: engineers, geologists and technicians are needed.
• Management: good planning and organisation keep operations efficient.

Capital, skilled labour and good management are all enabling factors. They make drilling easier and more profitable. The resource itself is the one thing that cannot be replaced.

Solution:

• B. Adequate capital: this supports drilling, so it does not make it unimportant.
• C. Adequate skilled labour: this also supports drilling.
• D. Good management: this improves efficiency, so it supports drilling.
• A. Depletion of reserves: if the oil reserves run out, there is nothing left to drill. Drilling then loses its importance, however much money, labour or management is available.

Tip: In "which factor makes something unimportant or unlikely" questions, look for the option that is a negative or limiting factor (depletion, shortage, scarcity, lack). The other options are usually positive factors. Here, "depletion" is the only negative word.