On the evening of 3 November a mother and daughter were found dead in their two-bedroom flat in Diswich. Both victims had suffocated and the police are treating the incident as suspicious. It is also known that: The victims were Mary Cauld, aged 24 years, and Sarah Cauld, aged 6 years. Mary Cauld's father had recently been released from prison. Sarah Cauld had been revealed HIV positive on 26 October. Gary Davison was Mary Cauld's ex-husband. A young man was seen near the flat on 2 November. The flat had not been broken into. Gary reported the deaths to the police at 6.45 pm on 3 November. Mary Cauld was owed £900 by Gary and had threatened to take him to court if he did not pay up soon.

Question: Mary Cauld could have killed her own daughter.
Options:
A. true, B. false, C. uncertain
Answer: "A"