This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
Contraindication of using a bar type direct retainer is: 
Select and explain. 
A. Used on a distobuccal on terminal abutments, B. When aesthetics demand less display of metal, C. When a push type of retention is needed, D. When a large tissue undercut is present
D: When a large tissue undercut is present
Answer: D: When a large tissue undercut is present 
Explanation: Gingivally approaching clasps (e.g. bar clasp) is contraindicated in severe soft tissue (gingival) undercut.
In such cases, occlusally approaching clasp configurations are more suitable.