Cause–Effect Analysis:\nI) Drucker will study one new subject every year.\nII) Drucker is considered an authority on a wide variety of subjects.

Introduction / Context:
This pair links a deliberate learning strategy (I) with a reputation outcome (II). In reasoning tests, systematic, repeated study plausibly builds breadth and depth, supporting the inference that I causes II, provided we read “will study every year” as representative of an ongoing habit rather than a one-off future isolated act.

Given Data / Assumptions:

• I) Commitment to study one new subject each year (a sustained learning plan).
• II) Recognition as an authority across many domains.
• We assume persistent application of I over time, aligning with the breadth implied by II.

Concept / Approach:
Cumulative practice produces competence. A structured, periodic expansion of knowledge domains (I) is a plausible cause of multi-domain authority (II). The reverse (II → I) is weaker: mere reputation does not necessitate adopting annual study.

Step-by-Step Solution:
1) Map the mechanism: yearly new-subject study → expanding knowledge portfolio.2) Accumulated breadth + depth over years → perceived authority across subjects.3) Therefore, I is the cause and II the resulting effect.

Verification / Alternative check:
Consider time consistency: authority across many areas rarely emerges without sustained learning behaviors like I.

Why Other Options Are Wrong:
(b) overstates reputation as a cause of study; (c) and (d) ignore a clear developmental pathway; (e) redundant.

Common Pitfalls:
Over-reading the future tense as a single future act; the test expects recognition of a general habit leading to expertise.

Final Answer:
Statement I is the cause and Statement II is its effect.