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
The greatest stress which may be produced in a material such that stress is directly proportional to the strain is known as: 
Select and explain. 
A. The elastic limit, B. The proportional limit, C. The yield strength, D. Modulus of elasticity
B: The proportional limit
Answer: B: The proportional limit 
Explanation: Proportional limit—Magnitude of elastic stress above which plastic deformation occurs.
The greatest stress which may be produced in a material such that stress is directly proportional to the strain is known as the proportional limit.
Reference: PHILLIPS’ SCIENCE OF DENTAL MATERIALS, 12th ed page no 48