To Grout or Caulk?

I live in a new construction building. My master bath has 12″marble tiled walls. On corner of the walls shows a hairline crack running vertically ( I guess due to settling).

My question is should I re-grout this area or use caulking. I heard somewhere that it is better to use caulkling since walls do move and the silicon caulking moves with them. Grout does not and this is why I have the crack.

Any suggestions for me?

By stableguy |