This is a true-except question, so I hunt for the single wrong line.
Three of the choices describe well-known facts. The emblem is a symmetric red cross whose arms are of equal length, which matches option A. India, like other signatory states, has legislation under the Geneva Conventions that makes improper use of the emblem an offence, which matches option C. The whole Red Cross system grew out of agreements signed in Geneva, which matches option D.
That leaves option B. Ownership of the Red Cross emblem belongs strictly to the Red Cross and Red Crescent movement and to recognised army medical services during war. The UN is a separate body with its own blue olive-branch emblem and is not entitled to display the Red Cross sign. Because that claim is incorrect, it is the exception.
\[\boxed{\text{B. Can be used by UNO personnel}}\]