Explanation:

Amazon Translate is AWS's neural machine translation service that provides high-quality language translation. It is specifically designed for translating text between languages, making it the most appropriate service for this e-commerce use case.

• Amazon Polly is a text-to-speech service that converts text into lifelike speech
• Amazon Transcribe is an automatic speech recognition service that converts speech to text
• Amazon Textract is a document analysis service that extracts text and data from scanned documents

For translating product descriptions from English to French and Japanese, Amazon Translate is the correct choice as it supports over 75 languages and can handle the translation needs of a global e-commerce platform efficiently.