The dog was sick of remaining frightened by stronger animals

The correct answer is option 'A' - remaining frightened by stronger animals. The dog's frustration and weariness can be attributed to its constant state of fear and anxiety when confronted with stronger animals. This answer can be explained in detail as follows:

Introduction:
- The given statement suggests that the dog is fed up with something and provides four options to choose from.
- We need to identify the option that best describes the reason for the dog's frustration.

Explanation:
The dog's dissatisfaction can be understood by analyzing each option:

a) Remaining frightened by stronger animals:
- Dogs are naturally territorial and can feel threatened by other animals, especially if they are stronger.
- If the dog is constantly encountering stronger animals that intimidate or pose a threat to it, it would lead to an ongoing state of fear and anxiety.
- Over time, this fear can become exhausting and overwhelming, causing the dog to feel sick of it.

b) Himself:
- This option does not provide a valid reason for the dog's frustration.
- It is unlikely that the dog would be sick of itself as it cannot change its own nature or behavior.

c) Barking:
- Although excessive barking can be irritating for both the dog and its owner, it is not necessarily a reason for the dog to feel sick of something.
- Barking is a natural form of communication for dogs and can be a way for them to express their needs or alert others to potential dangers.

d) Bad food:
- While it is possible for dogs to become sick or dissatisfied with their food if it is of poor quality or causing digestive issues, this option does not address the dog's overall state of being sick of something.

Conclusion:
- The dog's frustration and weariness are best explained by the option 'A' - remaining frightened by stronger animals.
- The constant state of fear and anxiety when confronted with stronger animals can be exhausting and overwhelming for the dog, leading to its dissatisfaction and desire for a change.