arXiv:2506.06727v1 Announce Type: new Abstract: Large Multimodal Models (LMMs) have demonstrated remarkable problem-solving capabilities across various domains. However, their ability to perform mathematical reasoning when answer options are represented as images--an essential aspect of multi-image comprehension--remains underexplored. To bridge this gap, we introduce VisioMath, a benchmark designed to evaluate mathematical reasoning in multimodal contexts involving image-based answer choices. VisioMath comprises 8,070 images and 1,800 multiple-choice questions, where each answer option is an image, presenting unique challenges to existing LMMs. To the best of our knowledge, VisioMath is the first dataset specifically tailored for mathematical reasoning in image-based-option scenarios, where fine-grained distinctions between answer choices are critical for accurate problem-solving. We systematically evaluate state-of-the-art LMMs on VisioMath and find that even the most advanced models struggle with this task. Notably, GPT-4o achieves only 45.9% accuracy, underscoring the limitations of current models in reasoning over visually similar answer choices. By addressing a crucial gap in existing benchmarks, VisioMath establishes a rigorous testbed for future research, driving advancements in multimodal reasoning.