When the king was accompany with his stalwart bodyguards, he felt safe walking among his people.
Which of the following phrases given below the sentence should replace the phrase printed in bold letters to make the sentence grammatically correct? Choose the best option among the five given alternatives that reflect the correct use of phrase in the context of the grammatically correct sentence. If the sentence is correct as it is, mark “No improvement required” as the answer.

The correct answer is "was accompanied by his".

Step-by-step Explanation:

1. Analyze the original phrase: The sentence contains the phrase "was accompany with his".
2. Identify the grammatical errors:
- Passive Voice construction: The action is performed on the subject ("the king") by the agent ("his stalwart bodyguards"). In passive voice, the verb structure should be a form of "to be" + past participle of the main verb. The past participle of "accompany" is "accompanied". Therefore, "was accompany" is grammatically incorrect and must be changed to "was accompanied".
- Preposition usage: The verb "accompany" in the passive voice is followed by the preposition "by" (to indicate the agent performing the action), not "with". Thus, "accompanied by" is the correct prepositional phrase.
- Pronoun agreement: The subject is "the king" (singular, masculine), so the singular possessive pronoun "his" is correct. The option "their" would be plural and incorrect.
3. Evaluate the options:
- "is accompany with his": Incorrect verb form ("accompany") and incorrect preposition ("with").
- "were accompanied by his": Incorrect subject-verb agreement. The subject "the king" is singular, so it requires the singular verb "was" instead of the plural verb "were".
- "was accompanied by their": Incorrect pronoun agreement. The plural pronoun "their" does not match the singular subject "the king".
- "was accompanied by his": Correct. It uses the proper passive verb form ("was accompanied"), the correct preposition ("by"), and matches the singular subject in number and pronoun ("his").