Final answer:
Option B is the most effective informal reading inventory for Spanish dominant ELLs as it promotes dialogue and language development by having students discuss the English passage in their own words, with the teacher offering language support.
Step-by-step explanation:
Among the given options, Option B, where students talk in their own words about what they have read, and the teacher supports their discussion by supplying language as needed, would be the most effective informal reading inventory. This approach helps students better understand the reading by allowing them to articulate their comprehension and engage in a dialogue about the text, which can be a powerful way to promote English language and literacy development. It enables students to practice close-reading in a safe, informal setting and prepares them for writing a more formal essay by encouraging them to record their initial impressions and discuss them with support from the teacher.
In contrast, Options A, C, and D are less interactive and do not foster as much opportunity for language development. True or false questions (Option A) can be limiting, and while having students rate the difficulty of the passage (Option C) provides insight into their comprehension level, it does not actively develop language skills. Option D, writing sentences, although valuable, does not offer the immediate feedback and collaborative benefits that oral discussion provides.