The correct answer is confidence.

The Azure Read API returns recognized text in nested structures such as pages, lines, and words and each word or token typically includes a numeric confidence field that indicates how closely the extracted handwritten token matches the recognized text. The confidence value is usually expressed as a number between 0 and 1 and represents the model's estimated probability for that specific token.

score is incorrect because the Read JSON does not use a per-token key named score to convey match strength.

accuracy is incorrect because the service does not provide a per-token accuracy field and it instead reports per-token confidence values.

certainty is incorrect because that key is not used in the Read API responses and the standard key for token-level match information is confidence.

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