Here is a goal: How to cut the mesh for your DIY bbq?

How would you accomplish this goal?

Choices:
(A). Put the wire mesh under the Altoids tin. Cut with an X-Acto knife about 1/2 inches beyond the tin.;
(B). Put the wire mesh over the Altoids tin. Cut with an X-Acto knife about 1/2 inches beyond the tin.;
(A).