Step 1: Pick out the key phrases:
Three phrases stand out in the statement: understand the world, think rationally, and use resources effectively. Each phrase refers to a mental ability used to deal with the surroundings.
So the answer must be a mental ability and not a feeling or a trait.
Step 2: Sort the four terms into groups:
Attitude and personality belong to the group of tendencies and traits that show how a person usually feels or acts. Self-actualisation belongs to the group of motives and needs. Intelligence belongs to the group of mental abilities.
Only the ability group can fit the statement.
Step 3: Link the statement to a known theorist:
The well known Wechsler definition says that intelligence is the global capacity to act with purpose, think rationally and deal effectively with the environment. The question is almost a paraphrase of it.
This confirms the ability group.
Step 4: Reject attitude:
An attitude is a settled evaluation, such as liking cricket. It tells us a person's stance and not how well the person solves problems. So attitude is out.
Step 5: Reject personality:
Personality describes stable patterns such as being shy or outgoing. Two people with equal reasoning power can have very different personalities. So personality is out.
Step 6: Reject self-actualisation:
Self-actualisation is the desire to reach one's full potential. It is a need at the top of Maslow's pyramid, not a capacity for reasoning. So it is out.
Step 7: Confirm intelligence:
Only intelligence fits both the group test and the definition test, so the correct choice is the third option.
Final Answer:
Intelligence is the term that fits, so option 3 is correct.
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