The correct answer is: B. Someone has cut the telegraph wires.
The other options are incorrect because they do not use the correct verb tense. The sentence is in the passive voice, so the verb “cut” must be in the past participle form, “cut.” Option A is incorrect because it uses the present participle form, “cutting.” Option C is incorrect because it uses the past tense form, “cut.” Option D is incorrect because it uses the plural form of the verb, “have.”
The sentence “The telegraph wires have been cut” means that someone cut the telegraph wires in the past. The passive voice is used in this sentence because the focus is on the action of cutting the telegraph wires, not on the person who did it.