Maxim and Inference — “The secret of success is constancy of purpose.” Which conclusion(s) are justified?

Introduction / Context:
The aphorism states that unwavering focus (constancy of purpose) underpins success. We must decide which conclusion logically resonates with this thesis without importing unrelated proverbs or claims.

Given Data / Assumptions:

• Core idea: success correlates with steady, persistent pursuit of a goal.
• No claim is made about physical processes or unrelated sayings.

Concept / Approach:
Conclusion II (“Single-minded devotion is necessary for achieving success.”) captures the intended meaning of constancy of purpose. Conclusion I (“Constant dripping wears the stone.”) is an independent proverb; it shares a persistence theme but is not a logical consequence of the given statement.

Step-by-Step Solution:

Verification / Alternative check:
Even if I is thematically aligned, logical following requires entailment from the given statement, not mere similarity in theme.

Why Other Options Are Wrong:

• I alone or Both: I is not deduced from the given sentence.
• Either / Neither: II is a direct restatement and thus follows.

Common Pitfalls:
Equating thematic resonance with logical entailment; importing external sayings.

Final Answer:
Only conclusion II follows