Statement–Assumption (Deterrence via Notice): Statement: “Private property. Trespassers will be prosecuted,” reads a notice on a plot of land. Assumptions: I) Many passers-by will read the notice and refrain from trespassing. II) The threat of prosecution is sufficiently deterrent for would-be trespassers.

Introduction / Context:
Threat notices aim to deter undesirable behavior. The posted warning is useful only if it reaches the intended audience and if its threatened consequence matters to them. We must isolate the minimal beliefs that must be true for the notice to function as intended.

Given Data / Assumptions:

• Notice content: “Trespassers will be prosecuted.”
• Goal: Discourage entry onto private land.
• Assumption I: People will see/read the notice and modify behavior.
• Assumption II: Fear of legal action deters trespass.

Concept / Approach:
Use the negation test. If people do not read the notice (negate I), the sign cannot influence behavior. If they read it but are indifferent to prosecution (negate II), the sign’s threat lacks bite. Both assumptions are jointly necessary for deterrence to work in the intended manner.

Step-by-Step Solution:
1) Negate I: If almost no one reads/notices the sign, it yields no behavior change.2) Negate II: If prosecution does not deter (e.g., apathy or disbelief), the sign’s threat is ineffective.3) Therefore, both I and II must hold for the notice to serve its deterrent function.

Verification / Alternative check:
Real-world compliance with signage generally depends on both communication reach (visibility, legibility) and consequence credibility (perceived risk). Removing either factor undermines deterrence.

Why Other Options Are Wrong:
“Only I” forgets about consequence salience. “Only II” assumes awareness without communication. “Either” is too weak: both are needed. “Neither” is plainly inconsistent with the purpose of warning signs.

Common Pitfalls:
Assuming one factor (threat) suffices without communication, or vice versa. Deterrence requires both exposure and credible sanction.

Final Answer:
Both Assumptions I and II are implicit.