Bert, an Habitual Burglar, Breaks into a Block of Retirement

Bert, an habitual burglar, breaks into a block of retirement flats at night. He enters Maud's flat. Maud is an elderly lady with a weak heart. She interrupts Bert while he is rifling through her cupboards. Maud suffers a heart attack due to shock and dies. Which of the following is most likely to apply?

A) Bert will be convicted of murder because it was virtually certain that Maud would have a heart attack and die and Bert realised this.
B) Bert will be convicted of attempted murder.
C) Bert will not be convicted of unlawful act manslaughter because the reasonable man would not have recognised the risk of some harm.
D) Bert will be convicted of unlawful act manslaughter. The act of burglary became dangerous when Bert saw that Maud was an elderly lady and realised that there was a risk of some harm to her.