Final answer:
Generation X is the workforce generation category that is ambitious but lacks loyalty to the organization, requiring motivating efforts for retention.
Step-by-step explanation:
The workforce generation category characterized as ambitious but lacking loyalty to the organization is Generation X.
Generation X, born between the early 1960s and the 1980s, typically do not expect to stay with one employer for their entire career and have a reduced sense of loyalty towards organizations. Retaining Generation X workers requires making their work meaningful and motivating them through frequent rewards, praise, and feedback.