Construction blueprints in PDFs often contain a mix of text, symbols, linework, and diagrams . The requirements include understanding both visual layout (where systems are located) and textual annotations , producing summaries, and answering Q & A. That combination requires a multimodal generative AI approach—models that can reason over images and text together. Therefore, A is best.

OCR alone (B) can extract printed text, but it won’t reliably interpret diagram geometry, symbols, or spatial relationships (e.g., “electrical riser is on the east core near gridline B-4”). Text completion (C) is too generic and doesn’t address image understanding. Document summarization (D) is only one requirement (summary) and still depends on first extracting/understanding both visual and textual elements.

A multimodal solution can ingest the PDF pages as images (or rendered page images) plus extracted text, then answer questions grounded in both modalities. In practice, you may combine OCR and layout extraction with a multimodal LLM so the model can reference drawing regions, legends, callouts, and system diagrams to produce accurate explanations and field extractions.