Living organisms show

The correct answer is All of the above.

To understand why all of the options are correct, let us analyze the defining characteristics of living organisms step-by-step:

1. Self-replication and self-regulation: Living organisms have the ability to reproduce and create copies of themselves (self-replication) to ensure the continuity of their species. They also possess internal regulatory mechanisms (self-regulation or homeostasis) to maintain a stable internal environment despite changes in external conditions.
2. Evolution: Over generations, living populations undergo genetic changes in response to environmental pressures. This process of evolution leads to adaptation and the diversity of life on Earth.
3. Response to external stimuli: All living things can sense their surroundings and respond to physical, chemical, or biological stimuli in their environment (e.g., plants growing towards light, or animals reacting to sound or temperature changes).

Since self-replication and self-regulation, evolution, and response to external stimuli are all fundamental characteristics of living organisms, the correct choice is indeed "All of the above".