Which sentence would be the most effective opening for a story about a mother of two who wanted to train and run a marathon?

A) Maria knew that she needed a change in her life, a new goal to work for--but what?
B) The children were asleep while Marie quietly tiptoed out the back door to go exercise.
C) What am I doing--a mother of two and training to run a marathon in six months? I must have lost my mind.
D) I woke up earlier than I'd ever woken up before and hit the alarm clock so my husband could go back to sleep.