Step 1: Analyze the passive sentence. "should not be offered" is a passive construction with a modal verb ('should'). The agent (the one performing the action) is implied, not stated.
Step 2: Introduce a logical subject. For general advice or rules, an implied subject like 'You', 'We', or 'One' can be used. The options provide 'You'.
Step 3: Change the verb form. The passive modal ('should not be offered') becomes an active modal ('should not offer').
Step 4: Rearrange the sentence. The indirect object 'Vegetarians' becomes the recipient of the action. The direct object 'meat' is offered. The correct structure is: "You should not offer meat to vegetarians."