Read the passage and answer the revision question. [1] City streets must serve buses, pedestrians, deliveries, and short-term parking. [2] General language about efficient curb use can hide difficult scheduling choices. [3] A policy can clarify its tradeoffs by describing a particular curb use. [4] However, a loading space can be reserved for fifteen-minute grocery deliveries during the morning rush. [5] The case shows how time limits and purpose shape access to the curb. The word 'However,' incorrectly signals contrast. Which replacement best introduces the specific curbside delivery policies case in sentence 4?