English Idiom — Determine the meaning in context. Sentence (corrected punctuation): Harassed by repeated acts of injustice, he decided to put his foot down.

Introduction / Context:
“To put one’s foot down” means to assert oneself firmly and refuse to give way. The sentence describes a tipping point after repeated injustices—precisely the moment when a person stops compromising and insists on fairness. This idiom is frequent in workplace conflicts, parenting, and public policy stand-offs.

Given Data / Assumptions:

• Sustained provocation: “repeated acts of injustice.”
• Decision point: he decides to act firmly.
• We must select the paraphrase emphasizing refusal to yield.

Concept / Approach:
The idiom centers on firmness, not exit. Resignation or withdrawal are forms of retreat, whereas putting one’s foot down is about standing ground. Accepting unconditionally is the opposite. Therefore, “not to yield” best captures the idiom’s decisive resistance.

Step-by-Step Solution:

Verification / Alternative check:
Paraphrase: “He decided not to yield.” The causal flow (injustice → resolve → firmness) reads naturally and aligns with standard definitions.

Why Other Options Are Wrong:

• resign: Leaves the field rather than resisting injustice.
• to accept the proposal unconditionally: Antonym of firmness.
• withdraw: Another form of retreat.

Common Pitfalls:
Confusing assertiveness with abandonment. The idiom indicates staying and standing firm, not quitting.

Final Answer:
not to yield