A company needs to extract key fields from scanned invoices, such as invoice number and total amount, with high accuracy. They want a managed service and plan to use human review for low-confidence results. Which combination of services should they use?
Document AI extracts invoice fields via prebuilt or custom models, returning per-field confidence scores. Human-in-the-Loop routes only low-confidence extractions to reviewers, satisfying the stem's accuracy requirement while keeping the service fully managed. This pairing directly matches the stated need for human review of uncertain results.
Why this answer
Document AI is Google Cloud's managed document understanding service with specialized parsers (Invoice, Expense, Form) that extract structured fields like invoice number and total amount with high accuracy. Human-in-the-Loop (HITL) integrates directly with Document AI to route low-confidence predictions to human reviewers, whose corrections feed back to improve the processor. Together they satisfy the managed-service and human-review requirements in one pipeline.
Exam trap
PMLE often tests the confusion between generic Vision/NLP APIs and purpose-built Document AI — candidates assume any OCR service can extract invoice fields, missing that schema-aware extraction plus a native human-review loop is the differentiator.
How to eliminate wrong answers
Option A is wrong because Vision API performs generic OCR/image labeling and Natural Language API does entity/sentiment analysis — neither understands invoice schema or returns structured invoice fields. Option C is wrong because Translation API only converts languages and AutoML Vision is a custom image classifier, not a document field extractor; you would have to build and label everything yourself. Option D is wrong because BigQuery ML and Vertex AI Prediction are general ML training/serving tools — they do not provide pre-built document parsing or a human-review workflow.