The correct option is B Gone
The first sentence is the statement and the second is the question. The questions says that the person wants to take the message for someone and so ‘someone’ is not present at the place of conversation. Now, the first sentence mentions ‘lunch’ and so we can safely presume that the action of ‘going’ to lunch has already happened. This makes the first sentence to be one of present perfect tense. The present perfect is made using the auxiliary verb 'have/ has' plus the 'past participle' of the main verb. Hence, Option B is the correct answer as it uses past participle of the verb “go,” i.e. “gone” as required by the present perfect tense of the sentence. The helping verb ‘has’ is already contained in the first sentence as the apostrophe s with ‘she.’
Option A would not be used as it is not the past participle of ‘go’. Options C and D cannot be used as they would render the sentence meaningless and grammatically incorrect.