Final answer:
While many educational resources are available in PDF format, like those from OpenStax, the Envision Algebra 1 Assessment Resources might not be available for free public download in PDF and may require purchase or special access. The correct answer is option A
Step-by-step explanation:
The Envision Algebra 1 Assessment Resources may not directly be available in PDF format for public download, especially if it's a proprietary resource. However, if there is an official PDF version provided by the publisher, it would typically only be accessible through purchase or with special access codes provided by the institution or instructor. Many textbooks are available in PDF format, as is the case with OpenStax resources. For example, content such as TEA AP® Physics 1 & 2: Algebra-Based by TEA (Texas Education Agency), and exercises from 2.E: Measurement and Problem Solving (Exercises) by Marisa Alviar-Agnew & Henry Agnew, can be accessed for free in web view or PDF through OpenStax.org, and for a low-cost in print. This shows that while some educational resources are freely available in PDF format, this may not be the same for all publications including the Envision Algebra 1 materials.