In this sentence completion question, choose the word that best completes the sentence: "You will have to undergo a _______ of tests before the interview."

Introduction / Context:
This vocabulary based question asks you to select the most appropriate noun to describe multiple tests occurring before an interview. The verb phrase "undergo a" and the noun that follows it form a common collocation in English, which helps you decide quickly if you are familiar with standard expressions used in academic and professional contexts.

Given Data / Assumptions:

• Sentence: "You will have to undergo a _______ of tests before the interview."
• We know there will be more than one test.
• Options: Large, Series, Design, Booklet.
• The blank must be filled with a noun that can logically be followed by "of tests".

Concept / Approach:
In English, multiple tests scheduled one after another are commonly described as a "series of tests". The key phrase is "a series of", which is frequently used with different nouns: "a series of meetings", "a series of experiments", and so on. The words "large", "design", and "booklet" do not combine naturally with "of tests" after "undergo". "Large" is an adjective and cannot be directly followed by "of tests" in this structure. "Design" and "booklet" do not represent a set or sequence of activities.

Step-by-Step Solution:
Step 1: Focus on the verb phrase "undergo a", which usually precedes a noun describing an experience, such as "operation" or "series of tests". Step 2: Consider what word typically appears before "of tests" when you talk about many different tests. The standard expression is "a series of tests". Step 3: Match this collocation with the options. "Series" is the only word among them that naturally forms "a series of tests". Step 4: Insert "series" into the sentence: "You will have to undergo a series of tests before the interview." Step 5: Read the complete sentence to verify that it sounds natural and precise.

Verification / Alternative check:
Test each incorrect option. "Undergo a large of tests" is clearly wrong because "large" is an adjective and requires a noun after it, for example "a large number of tests". "Undergo a design of tests" does not express the idea of multiple tests; "design" is something planned or created. "Undergo a booklet of tests" also fails, because a booklet is a physical collection of pages, not the experience of taking several tests. Only "series" correctly conveys a sequence of multiple tests.

Why Other Options Are Wrong:
"Large" cannot stand alone as a noun in this context and does not correctly combine with "of tests".

"Design" refers to a plan or pattern, not to a group of test events to be experienced.

"Booklet" is a small book and would be an object to read, not something you "undergo".

Common Pitfalls:
Students sometimes pick an adjective like "large" because they focus on the idea of "many tests". However, the structure "a large of tests" is grammatically wrong. When you see "a _______ of", check whether the blank is a noun that can appear before "of" and whether the entire phrase is a known collocation. Learning expressions such as "a series of", "a range of", and "a variety of" will help avoid this trap.

Final Answer:
The best choice is "Series", giving the sentence: "You will have to undergo a series of tests before the interview."