If all Martians vacation on Venus, then

Options

A. A being that does not vacation on Venus is not a Martian.
B. Anyone who vacations on Venus is a Martian.
C. No beings from Pluto vacation on Venus.
D. All beings from Venus vacation on Mars.

Explanation

To solve the question logically, we need to analyze the given statement: "If all Martians vacation on Venus." Based on this statement, we will evaluate the options provided to determine which one is true.

### Step-by-Step Solution:

1. **Understand the Given Statement**:
- The statement tells us that every Martian goes on vacation to Venus. This means that if something is a Martian, it must be vacationing on Venus.

2. **Evaluate Option A**:
- Option A states: "Does not vacation on Venus is not a Martian."
- Since all Martians vacation on Venus, if someone does not vacation on Venus, they cannot be a Martian. Therefore, this statement is true.

3. **Evaluate Option B**:
- Option B states: "Anyone who vacations on Venus is a Martian."
- This statement is not necessarily true because the original statement only confirms that all Martians vacation on Venus. It does not exclude the possibility that non-Martians could also vacation on Venus.

4. **Evaluate Option C**:
- Option C states: "No beings from Pluto vacation on Venus."
- This statement cannot be confirmed or denied based on the information provided. The original statement does not mention anything about beings from Pluto, so we cannot conclude anything about them.

5. **Evaluate Option D**:
- Option D states: "All beings from Venus vacation on Mars."
- Similar to Option C, this statement is not supported by the original statement. The original statement only discusses Martians and their vacationing habits, not beings from Venus.

6. **Conclusion**:
- The only statement that logically follows from the given information is Option A: "Does not vacation on Venus is not a Martian."

### Final Answer:
The true statement is **Option A**: "Does not vacation on Venus is not a Martian."