**Core concept**: Grammar (subjunctive mood). **Analysis**: The subjunctive mood uses the base form of the verb in clauses after expressions like 'essential that.' **B. It is essential that he submit...** is correct. **Wrong options**: - A. Uses 'was' instead of 'were' for hypothetical 'I.' - C. Incorrectly uses 'has' instead of 'had' for past wishes. - D. Uses 'listens' (indicative) instead of 'listen' (subjunctive). **Key point**: Subjunctive mood requires base verb form (e.g., 'submit,' 'be') in formal demands or suggestions.