The correct passive form of the given sentence is:

☀ He must be helped by you.

Let's break down the options:

1. He must helped by you. (Incorrect) This option is not in the correct passive voice construction. It lacks the appropriate form of the verb "to be" and the past participle "helped."

2. He must helped you. (Incorrect) This option is still in the active voice and changes the meaning of the original sentence. The original sentence suggests that "you" should help "him," but this option suggests that "he" should help "you."

3. He must get help from you. (Incorrect) This option is still in the active voice and changes the meaning of the original sentence. It suggests that "he" needs to receive help from "you," but the original sentence implies that "you" should actively provide the help.

4. He must be helped by you. (Correct) This sentence correctly uses the passive voice and conveys the same meaning as the original sentence. It uses the correct form "must be helped" to express the obligation for someone else ("you") to help "him."