sucker on lemon tree sapling

Question

So I’m not sure if I should prune this branch all the way down because I’m not sure if it’s a sucker or not.

Answer 1

Well I thought it posted a photo but I guess not.

Answer 2

Sucker growth would come from the roots or may be growing just below a graft line on the tree.

https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-sucker-removal-and-tree-sucker-control.htm