The correct answer is A: Custom Vision. Custom Vision is part of Azure Cognitive Services and is specifically designed to build, deploy, and improve custom image classifiers. It is ideal for identifying specific products or objects in images, making it suitable for processing images from retail stores and identifying competitor products. The other options, such as Form Recognizer, Face, and Computer Vision, are designed for different tasks: Form Recognizer for extracting text and structure from documents, Face for facial recognition and analysis, and Computer Vision for general image analysis and extraction of information but not for highly customized scenarios like identifying specific products.