Final answer:
In 'The Witch of Blackbird Pond,' Thanksgiving is canceled due to a harsh winter that makes it impossible to gather for the celebration.
Step-by-step explanation:
In 'The Witch of Blackbird Pond,' Thanksgiving is canceled due to option a) a harsh winter that makes it impossible to gather for the celebration.
The story takes place in the Connecticut colony, and harsh winters were common in New England during that time period. The colonists faced challenges such as cold weather, storms, and a scarcity of food, which made it difficult to hold a Thanksgiving feast.