In this English vocabulary question, select the one word that best names the outer layer of the cerebrum, the part of the brain composed of folded grey matter that plays a major role in consciousness.

Introduction / Context:
One word substitution questions check how well you know precise technical or scientific terms that are often used in educated English. Here, the phrase describes a specific part of the human brain, and you must match it with the correct anatomical term. This tests both your general knowledge and your vocabulary, which is valuable for exams and for reading scientific articles or health related news.

Given Data / Assumptions:
• The description refers to the outer layer of the cerebrum in the brain. • It is composed of folded grey matter. • It plays an important role in consciousness and higher mental functions. • The options are "victor", "cortex", "scrub", and "capered".

Concept / Approach:
The cerebrum is the largest part of the human brain. Its outer surface is heavily folded and is made of grey matter. This outer layer is known in biology and medicine as the "cerebral cortex". The word "cortex" is used more generally in science to refer to the outer layer of an organ or structure. Therefore, the correct one word substitute must be "cortex". A good approach is to recognise the domain, here basic biology, and then recall the standard technical term used in textbooks and classes.

Step-by-Step Solution:
Step 1: Identify that the question is about brain anatomy, specifically the cerebrum. Step 2: Recall that the folded grey matter on the surface of the cerebrum is called the cerebral cortex. Step 3: Note that the key word in that phrase is "cortex", which literally means outer layer. Step 4: Compare the options and find that only "cortex" is a biological term related to an outer layer. Step 5: Confirm that the other options do not match any known brain structure, so they can be safely rejected.

Verification / Alternative check:
You can verify by recalling other uses of the word "cortex". For example, in botany we talk about the cortex of a stem or root, meaning its outer layer. In zoology and human anatomy, the adrenal cortex is the outer region of the adrenal glands. The pattern is clear: cortex equals outer layer. The description in the question strongly fits this pattern, so the match is reliable.

Why Other Options Are Wrong:
"Victor" means the winner in a contest or battle. It has nothing to do with brain structures. "Scrub" refers to cleaning by rubbing, or low growing vegetation. It is unrelated to brain anatomy. "Capered" is the past tense of "caper", meaning to skip or dance about in a lively way. This is a verb and does not name any part of the brain.

Common Pitfalls:
Students who have not revised basic biology may try to guess based only on sound, which is risky. Some may confuse "cortex" with "cortexin" or other medical sounding words they have half heard. Others may be distracted by completely unrelated but familiar words such as "victor". To avoid such errors, maintain a simple habit of reviewing key scientific terms that frequently appear in school and competitive exams. These terms are repeatedly tested because they combine vocabulary and general knowledge in one question type.

Final Answer:
The correct one word substitute is cortex.