In medical applications, the biodegradability of materials is a crucial factor, especially for implants, sutures, and drug delivery systems where the material is expected to break down safely within the body over time.

Among the given options:

- Polylactic acid (PLA) is a biodegradable polymer derived from renewable resources like corn starch or sugarcane. It degrades into non-toxic lactic acid, which is naturally metabolized by the body. This makes PLA highly suitable for temporary medical devices such as resorbable sutures, implants, and tissue engineering scaffolds.

- In contrast, Polyethylene (PE), Polystyrene (PS), and Polyvinyl chloride (PVC) are non-biodegradable synthetic polymers widely used in medical packaging and devices but do not break down within the body. Their persistence can lead to long-term foreign body reactions if implanted.

Therefore, the correct answer is Polylactic acid (PLA) due to its biocompatibility and predictable biodegradation profile, making it the most commonly recognized biodegradable material in medical contexts.

Reference: Biomaterials Science: An Introduction to Materials in Medicine, 3rd Edition, Volume 1, Chapter 5, pp. 130-135.