What increases believability of branches in a line drawing of a tree?

Correct answer: Gradual thinning of smaller branches from the main trunk

Direct answer: D, by gradually thinning smaller branches as they extend from the main trunk. A believable tree drawing needs lines that suggest how the tree is organised. The trunk is generally the main support, larger branches grow from it, and smaller branches divide farther outward. A gradual change in line thickness makes these relationships easier to see and gives the branches a more natural progression. Option A is wrong because making every branch equally thick removes the difference between trunk, major branches, and twigs. Option B is wrong because branches need a directional growth pattern; random lines do not clearly describe structure. Option C is wrong because removing the trunk removes the visual source from which the branches emerge. Option D is correct because controlled thinning communicates branching order and structure. This does not mean every real tree is identical; it means the drawing should show a coherent relationship of thickness. Memory cue: trunk to branch to twig—large, smaller, smallest.