The correct passive form of the given sentence is:

☀ This watch need not be wound by you.

Let's break down the options:

1. This watch need not be wound by you. (Correct) This sentence correctly uses the passive voice and conveys the same meaning as the original sentence, indicating that "you" are not required to wind this watch.

2. This watch does not wind. (Incorrect) This sentence is in the active voice, not the passive voice. It doesn't represent the passive form of the original sentence.

3. This watch need not be wounded. (Incorrect) This sentence is in the passive voice, but it uses the wrong past participle "wounded." The correct past participle of "wind" in this context is "wound," so the correct form should be "This watch need not be wound."

4. This watch need not be winded up. (Incorrect) This sentence is in the passive voice, but it uses the incorrect past participle "winded." Again, the correct past participle of "wind" in this context is "wound," so the correct form should be "This watch need not be wound up." However, this option still changes the meaning slightly from the original sentence, which does not mention "winding up."