Read the passage about riparian vegetation, wildlife, and streamside management. Then answer the question. Overall, on what kind of basis do the author’s assertions in this passage appear to rest?

Introduction / Context:
The passage about riparian vegetation is written in an informative and instructive style. It explains how vegetation stabilises stream banks, filters sediment, and provides habitat and winter cover, and it also discusses insects, dead trees, diseases, and the role of extension agents. The question asks what kind of foundation or basis underlies the author’s assertions. In other words, we must decide whether the passage is based on emotion, opinion, weak evidence, or solid scientific information.

Given Data / Assumptions:

• The passage uses technical words such as riparian vegetation, stream banks, and winter cover.
• It discusses specific ecological functions such as sediment filtering, water absorption, and late summer stream flow.
• It identifies particular wildlife groups such as upland game birds and nongame mammals.
• It refers to disease organisms, pesticide misuse, and advice to contact a local extension agent.
• The tone is calm, factual, and practical rather than emotional or dramatic.

Concept / Approach:
To determine the basis of the assertions, we look at the language, the type of details, and the tone. The use of technical terms, ecological processes, and references to extension agents suggests that the writer is drawing from scientific knowledge and practical field studies. The passage does not sound like a personal rant or a poetic reflection. It also does not rely on myth or folklore. Instead, it reads like an educational extension or conservation document that summarises research based knowledge in accessible language.

Step-by-Step Solution:
Step 1: Examine option A, which says the assertions are rash opinions with little observation. This is not consistent with the careful explanation of processes and the detailed ecological roles described. Step 2: Examine option B, which claims the basis is deeply held emotions. The passage is not emotional in tone; it is descriptive and instructive. Step 3: Examine option D, which suggests inconclusive evidence from weak field studies. Nothing in the passage suggests that the evidence is inconclusive or doubtful. The author speaks with confidence and clarity about the functions of riparian vegetation. Step 4: Examine option E, which refers to myths and oral stories. The passage clearly refers to scientific concepts and modern management advice, not legends or folklore. Step 5: Examine option C, which says the assertions are based on facts derived from scientific literature. The style, terminology, and reference to extension agents strongly support this view. The passage appears to condense established research into practical guidance.

Verification / Alternative check:
A good verification method is to ask what type of publication might contain such a passage. The content would fit well in an extension bulletin, environmental management guide, or conservation handbook that draws on scientific studies. This makes option C the most reasonable choice. There is no sign of personal ranting, poetic storytelling, or speculative opinion, which rules out the other options.

Why Other Options Are Wrong:
Option A is wrong because the detailed explanations and specific terms clearly show careful observation and study, not rash opinion. Option B is wrong because emotion is not the dominant feature; the tone is calm and informative. Option D is wrong because the author does not express doubt or uncertainty about the effects described. Option E is wrong because there is no mention of myths or legendary stories; everything is presented in scientific and practical language.

Common Pitfalls:
Students sometimes confuse an accessible, non technical writing style with opinion based content. However, clear explanations and everyday language can still be grounded in research and scientific data. It is important to look for clues such as the type of examples given, the presence of technical terms, and references to expert resources like extension agents. These all signal a factual, research based foundation for the passage.

Final Answer:
The assertions in the passage appear to be based on facts and information derived from scientific and technical literature.