Critical Reasoning — Protein Extraction Claim and Valid Conclusions Statements: • About 50% of animal by-products (hair, skin, horns, etc.) is edible protein. • American chemists have developed a method of isolating 45% of this protein. • They used an enzyme developed in Japan to break down soya protein. What can be concluded?

Introduction / Context:
This question tests whether the offered conclusions logically follow from the given scientific claims. We are told some facts about the proportion of edible protein in animal by-products, that U.S. chemists can isolate 45% of that protein, and that they used a Japanese-developed enzyme (originally used for soya protein). We must decide if the conclusions about Americans' capability to develop enzymes and about protein composition similarity are warranted.

Given Data / Assumptions:

• Animal by-products contain ~50% edible protein.
• American chemists isolated 45% of this protein.
• They used a Japan-developed enzyme for soya protein breakdown.
• No claim is made about Americans' inability to develop enzymes.
• No biochemical equivalence between animal by-product protein and soya protein is stated.

Concept / Approach:
We must separate what is explicitly stated from what is merely plausible. Using a foreign-developed tool does not imply an inability to develop a similar tool domestically. Likewise, using an enzyme that works on soya protein does not prove identity of composition between soya protein and animal by-product protein; enzymes can act on different substrates or overlapping peptide bonds without full compositional identity.

Step-by-Step Solution:

Verification / Alternative check:
Look for missing links: the premises lack any general claim about American enzyme research capability and lack any biochemical compositional equivalence claim. Hence, both conclusions overreach.

Why Other Options Are Wrong:

• Only I or only II: each asserts information not provided.
• Either I or II / Both: at least one would need to be entailed; neither is.

Common Pitfalls:
Confusing “used a tool from X” with “cannot build a tool,” and assuming functional overlap means identical composition.

Final Answer:
Neither I nor II follows