A company has set up a translation tool to help its customer service team handle...

Comprehensive and Detailed Explanation From Exact AWS AI documents:

BLEU is a widely used metric for evaluating machine translation by comparing machine-generated translations against reference (human) translations.

In this scenario:

Both systems are evaluated on the same dataset

The goal is to compare model output against human output

AWS ML evaluation guidance describes BLEU as suitable for relative comparison of translation quality across systems.

Why the other options are incorrect:

Absolute quality (A, C) is difficult to measure without human judgment.

BERTScore (D) is more computationally complex and less standard for operational comparisons.

AWS AI document references:

Evaluating Machine Translation Models

NLP Model Evaluation Metrics

Comparing AI and Human Translations