Final answer:
The need for achievement in McClelland's three-needs theory has been the subject of extensive research and is said to be critically linked to business success and entrepreneurial behavior.
Step-by-step explanation:
Of the needs identified in the three-needs theory, achievement has been researched the most. This is based on McClelland's extensive studies including 'The effect of need for achievement on recognition of need-related words' by McClelland & Liberman (1949). McClelland's work on the need for achievement explored how individuals with a high need for achievement are usually more successful in business and entrepreneurial activities because they have a strong desire for performance improvement and excellence in tasks.