Concept:Physiological variation refers to differences in internal body functions or processes among individuals of the same species.
Explanation:Blood pressure is an internal body function.
It changes from person to person due to health, age, genetics, and lifestyle.
This makes variation in blood pressure a physiological difference.
Beak shape, fur color, and leaf shape are physical or structural features, not internal functions.
Therefore, they are examples of morphological variation, not physiological variation.
Answer:A. Variation in blood pressure among individuals.