If you have answered d), you have passed the Royal Serious Comic Sans Crime Squad. Welcome to the team.
a) Do nothing. This clear mental aberration is none of your business
b) Stand up, point to the blasphemer and shout "COMIC SANS KLAXON!" at the top of your voice
c) All of b) but with added stamping on the offender's phone
d) Employ your ninja tracking skills to follow the Comic Sans Criminal throughout his day, noting his place of work, his circle of friends and - eventually - where he lives. Then, crap through his letterbox, it being the only language these curs understand
The Royal Serious Comic Sans Crime Squad: "Making Britain a safer place to live and work".
Ninja Edit, 13th December: Readers may be disappointed by the fact that the scientists at CERN are using The Font of Champions in their presentation on the discovery of the Higgs Boson.
However, I have been assured that it is a newly-discovered font called COMIC CERNS.
"And on this slide," said the CERN chief, "Next to the smily face wingding, is final proof of the Higgs Boson"
"Any questions?" the CERN supremo wraps up, "Click on the animated mail box on our [blink] new webpage [/blink]"
"I'm sorry," says one of the press pack at the CERN presentation, "I can't read your presentation. Can you stop it from scrolling? The bold pink text is hurting my eyes."