In the following sentence, choose the most appropriate word to fill the blank: "For three months, I have had a __________ headache."

Introduction / Context:
This question checks your understanding of vocabulary related to time and duration of medical conditions. The sentence is "For three months, I have had a __________ headache." The blank needs a word that correctly describes a condition continuing for an extended period. Knowing the precise meaning of words such as "chronic", "lifelong", "settled", and "inbred" is important for both general English and specific contexts like health and medicine.

Given Data / Assumptions:

• The speaker has had a headache for three months.
• We must choose a word that logically describes a condition lasting for that period.
• Options include "inbred", "settled", "chronic", "lifelong", and "sudden" (added as an extra distractor).
• We assume everyday medical and general English usage.

Concept / Approach:
In medical and general English, "chronic" describes an illness or symptom that continues for a long time or keeps coming back, as opposed to "acute", which describes a sudden and severe condition. The keyword in the sentence is "for three months", emphasising duration. Therefore, we should look for a word whose core meaning fits the idea of a long lasting or persistent problem. Other options may relate to different ideas, such as origin, nature, or intensity, but not to the typical description of a prolonged condition.

Step-by-Step Solution:
Step 1: Identify the key clue "for three months". This clearly shows the headache is not a one time incident but a continuing issue. Step 2: Consider "chronic". Chronic means long lasting, persistent, or constantly recurring, particularly when used about diseases, symptoms, or problems. Step 3: Check "inbred". Inbred usually refers to characteristics that exist from birth due to close genetic relationships, or to qualities deeply rooted in a person or group. It does not normally apply to a headache in this context. Step 4: Consider "settled". Settled can mean fixed, stable, or resolved, and does not naturally describe the ongoing presence of a headache over months. Step 5: Check "lifelong". Lifelong means lasting for a person's entire life. Three months is serious but not equivalent to a whole life, so the word does not match the time frame in the sentence. Step 6: "Sudden" is the opposite of something developing or continuing over time, and therefore conflicts with the idea of "for three months". Step 7: Conclude that "chronic" is the word that fits both the meaning and the typical collocation "chronic headache".

Verification / Alternative check:
Native usage confirms this choice. Expressions such as "chronic back pain", "chronic cough", and "chronic headache" are widely used to describe persistent medical issues. If we insert "chronic" into the sentence, we get "For three months, I have had a chronic headache," which reads naturally and correctly. Trying "lifelong headache" or "settled headache" feels unnatural and does not match common English patterns, which further verifies that "chronic" is the standard and correct choice.

Why Other Options Are Wrong:
"Inbred" relates to inherited characteristics and genetics, not to a headache experienced for a limited period. "Settled" suggests something has become stable or fixed, and is usually used for arrangements, lifestyles, or disputes rather than for ongoing pain. "Lifelong" greatly exaggerates the time span; three months is serious but far from an entire life. "Sudden" contradicts the idea of a problem continuing over months and instead suggests something that appears quickly at one point in time. None of these alternatives fit the clear duration clue in the sentence.

Common Pitfalls:
Students sometimes misinterpret "chronic" to mean "severe", but the true core meaning is "long lasting" or "persistent". Another pitfall is treating "lifelong" as a stronger version of "chronic" without noticing the mismatch in time frame given in the sentence. Always pay attention to words like "for three months", "for years", or "since childhood", which point directly to the need for a duration related adjective.

Final Answer:
The correct word to complete the sentence is "chronic", giving "For three months, I have had a chronic headache."