The correct Active/Passive form of the given sentence is:

☀ The Counsel was told by the assessee to file his return of income.

Explanation:

Explanation for other options:

☀ The Counsel of the assessee was told to file his return of income. This option is in the passive voice, but it changes the meaning slightly by introducing the phrase "of the assessee," which suggests ownership or belonging to the assessee. The original sentence does not imply such ownership.

☀ The Counsel was asked to file his return of income by the assessee. This option is in the passive voice, but it changes the meaning by using the verb "asked" instead of "told." The original sentence uses "told," which is more assertive and direct.

☀ The Counsel has been told to file his return of income by the assessee. This option uses the present perfect tense ("has been told"), which suggests a connection to the present or recent past. The original sentence is in the simple past tense, so the correct form should be "The Counsel was told by the assessee to file his return of income."