This mischief could not be done by a child.
This mischief could not been done by a child.
This mischief could not have been done by a child.
This mischief a child could not have been done.
Answer is Wrong!
Answer is Right!
The correct answer is: C. This mischief could not have been done by a child.
The other options are incorrect because they use the wrong verb tense. The sentence is in the past tense, so the verb “could” should be used. The verb “could not been” is not a correct verb tense. The verb “a child could not have been done” is not a complete sentence.
The sentence “A child could not have done this mischief” means that it is not possible for a child to have done this mischief. This could be because the mischief is too complex or difficult for a child to do, or because the mischief is morally wrong and a child would not do it.