For the annual Grand Elf Light Show, five elves are tasked with walking around the courtyard (see the map) while each holding the end of a light chain, with which they dramatically wave around in time to the music. The other end of each light chain is plugged into a socket placed at the center of the courtyard (marked on the map).
Each elf follows their individual path, with all paths marked in different colors. The goal is for all elves to meet at the center for the grand finale of the show.
However, there’s a tricky old picket in the courtyard. If any light chain wraps around it, the grant finale could end in chaos!
To ensure that no light chain is wrapped around the picket at the end of the show, which elf needs to adjust their path?
a. 🧝♀️🔵✨ Adele
b. 🧝♂️🟠🎁 Bea
c. 🧝🟡💡 Celina
d. 🧝♀️🟣❄️ Donna
e. 🧝♂️🟢🎄 Elli
Related control topic: Nyquist stability criterion