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

☀ All his calculations have been proved wrong.

Explanation for other options:

☀ All his calculations had been proving wrong. This option is not in the correct passive voice. It uses the active voice "had been proving," which is not the correct form for the passive construction. The correct form should be "had been proved wrong."

☀ All his calculations were proved wrong. This option is in the passive voice, but it changes the tense from present perfect ("have proved") to simple past ("were proved"). The correct form should maintain the present perfect tense in the passive voice: "All his calculations have been proved wrong."

☀ All their calculations had been proved wrong. This option uses "their" instead of "his," which changes the possessive pronoun and alters the meaning of the sentence. The original sentence refers to "his calculations," so the correct form should be "All his calculations have been proved wrong."