To make the plot linear, the events should follow a logical sequence in chronological order. The correct change to achieve this is:
a. Move D to the beginning
This way, the story would start with Marla's sister finding the shoes, which would explain why Marla can't find them and ends up wearing slippers, leading to her running to the bus stop. The new sequence would be:
- D: While Marla is eating breakfast, her little sister finds Marla's work shoes in the bedroom closet and walks away in them.
- A: After she finishes breakfast, Marla rummages through her bedroom closet looking for her work shoes.
- B: Marla can't find her work shoes, so she pulls on a pair of slippers.
- C: Marla runs to the bus stop in her slippers and gets on the bus to work.
This arrangement follows a logical timeline and maintains coherence in the plot.