We did not realize that the boys’ father had forbade them to keep there puppy.

1. A Option A: We did not realize that the boys' father had forbade them to keep there puppy.
2. B Option B: We did not realize that the boys' father had forbade them to keep their puppy.
3. C Option C: We did not realize that the boys' father has forbidden them to keep their puppy.
4. D Option D: We did not realize that the boys' father had forbidden them to keep their puppy.

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