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

☀ By whom was this glass broken?

Explanation for other options:

☀ By whom this glass was broken? This option is in the passive voice and is grammatically correct, but the word order is not as common or natural in English. The more common word order is "By whom was this glass broken?"

☀ By whom has this glass been broken? This option uses the present perfect tense ("has been broken"), 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 "By whom was this glass broken?"

☀ By whom is this glass broken? This option is in the passive voice, but it uses the present tense ("is broken"), which suggests a current state or ongoing action. The original sentence is in the simple past tense, so the correct form should be "By whom was this glass broken?"