At 10.00 on 2 September, a 25-year-old woman was found dead in her flat in the Highfield district of the city. She had been strangled. The victim, Mary Kelly, was a prostitute who had been working the streets for the past three years. The following facts are known: Mary Kelly had been HIV positive for the past 18 months. Mary Kelly had been trying to give up prostitution. Mary Kelly had been receiving treatment for depression. Mary Kelly had been threatened by a client the previous week. Mary Kelly had been seen arguing with a man outside her flat at 21.30 on 1 September. The man was described as being in his late 40s, about 1.75m tall, and wearing a dark suit. Mary Kelly's flat had been broken into twice in the past month.

Question: Mary Kelly was murdered by one of her clients.
Options:
A. true, B. false, C. uncertain
Answer: "C"