[Question] Which size fits best?

I ordered two watches: the Mondaine Evo2 40 mm and 35 mm. I can't decide which one fits my wrist best. My wrist has a circumference of 16 cm. Opinions are divided among people around me. I think the 40 mm watch looks the nicest. The 35 mm watch seems a bit like a children's watch.

Which size do you think would fit best?