Passage Summary: Hemoglobin in our blood carries oxygen. When it grabs one oxygen molecule, it changes shape to make it easier to grab the next one, until it's full.

Reasoning: Hemoglobin's ability to pick up oxygen increases as it binds to more molecules because the binding process physically changes the molecule's shape to accommodate more oxygen.

Analysis: Since this is a 'Most Strongly Supported' question, we must treat the premises as absolute facts and find a statement that logically follows from them. The stimulus describes a progressive physical change: each oxygen molecule 'opens' the hemoglobin further. Therefore, a hemoglobin molecule with more oxygen is physically more receptive than one with less. Look for an answer choice that makes a direct comparison between the molecule's states based on its current oxygen load.