**Core Concept**
Weber Fechner Law is a principle in psychophysics that describes the relationship between the physical magnitude of a stimulus and its perceived intensity. It states that the just-noticeable difference (JND) in a stimulus is proportional to the original stimulus intensity. This law is essential in understanding how sensory perception is related to the physical properties of stimuli.

**Why the Correct Answer is Right**
The Weber Fechner Law is a mathematical expression of the concept that as the intensity of a stimulus increases, the minimum amount of change needed to detect the difference also increases. This law is formulated as ΔI/I = k, where ΔI is the just-noticeable difference in the stimulus intensity, I is the original stimulus intensity, and k is a constant. This law is applicable to various sensory modalities, including vision, hearing, touch, and taste. It provides a fundamental understanding of how our brains process and perceive sensory information.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the Weber Fechner Law. The law is not related to the concept of absolute threshold, which is the minimum intensity of a stimulus that can be detected.

**Option B:** This option is incorrect because it is a concept from a different field of study. The concept of habituation refers to the decrease in response to a stimulus that occurs after repeated exposure, which is unrelated to the Weber Fechner Law.

**Option C:** This option is incorrect because it describes a different law in psychophysics. The Stevens' Power Law describes the relationship between the physical magnitude of a stimulus and its perceived intensity, but it is not the same as the Weber Fechner Law.

**Clinical Pearl / High-Yield Fact**
A key application of the Weber Fechner Law is in the field of sensory testing, where it is used to calculate the minimum detectable difference in sensory thresholds. This is particularly relevant in clinical settings where sensory function is impaired, such as in neurological or ophthalmological conditions.

**Correct Answer: D. Weber Fechner Law is a principle in psychophysics that describes the relationship between the physical magnitude of a stimulus and its perceived intensity.**

✓ Correct Answer: A. Magnitude of stimulus strength perceived is approximately propoionate to the log of the intensity of stimulus strength