Critical reasoning — assumptions (implicit): Statement: The organization should promote employees on the basis of merit alone and not on the basis of length of service or seniority. Assumptions: I. Length of service or seniority does not alone reflect merit of an employee. II. It is possible to determine and measure an employee's merit.

Introduction / Context:
This policy recommendation prioritizes merit over tenure or seniority for promotions. We must uncover what must be accepted for such a recommendation to be meaningful and implementable.

Given Data / Assumptions:

• Policy: Promote on merit alone; do not use length of service/seniority.
• Assumption I: Tenure or seniority does not reliably indicate merit.
• Assumption II: Merit can be assessed/measured.

Concept / Approach:
To justify rejecting seniority as a criterion, the recommender must assume that seniority is not a sufficient proxy for performance or capability (I). Additionally, to make a merit-only policy feasible, it must be possible to define and evaluate merit in practice (II). Without II, the recommendation is not actionable.

Step-by-Step Solution:

Verification / Alternative check:
Negate I: If seniority perfectly reflected merit, discarding it would be irrational. Negate II: If merit could not be determined, 'merit-only' promotions become impossible. Either negation undermines the recommendation, confirming that both I and II are implicit.

Why Other Options Are Wrong:

• Only I/Only II/Either/Neither: Each omits a necessary condition—either the rationale for excluding seniority or the feasibility of measuring merit.

Common Pitfalls:
Forgetting that practical recommendations require implementability. Policy logic hinges on both normative and operational assumptions.

Final Answer:
Both I and II are implicit