C# BoundingBox


How can I get a list of BoundingBox from GUID object in C#?
What I am trying to find is a point of an object, that is in the centre and in the lowest possible position.

Currently I have a list, that can contain either meshes or breps:
List jitterListM = Jitter(m);

Thank you,

Given a list of objects called “things” that inherit from GeometryBase:

var bottomPoints = things.Select(thing => thing.GetBoundingBox(true).PointAt(0.5, 0.5, 0));