Select the correct passive form of the given sentence.

Do not allow strangers into the society complex.

Strangers should not be allowed into the society complex.

The correct passive form of the given sentence is:

☀ Strangers should not be allowed into the society complex.

Explanation for all options:

1. Let strangers should be not allowed into the society complex. - This option is grammatically incorrect. The use of "should be not allowed" is not appropriate here.

2. Let strangers must not allow into the society complex. - This option is also grammatically incorrect. The structure "Let strangers must not allow" is not valid for forming a passive sentence.

3. Strangers should not be allowed into the society complex. - This is the correct passive form. The active sentence "Do not allow strangers into the society complex" has been transformed into the passive form "Strangers should not be allowed into the society complex."

4. Strangers should not have been allowed into the society complex. - This option is incorrect because it changes the tense of the sentence. The original sentence is in the present tense, while this option is in the present perfect tense, which alters the meaning.