Answer: D: The irascible dog growled and snarled whenever strangers neared the fence.
Explanation: The dictionary entry defines "irascible" as having or showing a tendency to be easily angered. In sentence D, the word "irascible" accurately describes the behavior of the dog. The dog's growling and snarling whenever strangers approached the fence demonstrates its tendency to become easily angered.
In contrast, the other sentences do not use "irascible" correctly.