In the following question, out of the four alternatives, select the alternative which is the best one-word substitute for the given definition: "A routine task, especially a household one."

Introduction / Context:
This one-word substitution question focuses on everyday vocabulary related to work and tasks in daily life. The definition given is "A routine task, especially a household one." Such words appear frequently in descriptions of domestic life, time management, and personal responsibilities, making them important for comprehension and precise expression.

Given Data / Assumptions:

We need a noun that means a routine or regular task, particularly in the context of the home.
The word should fit sentences like "daily household ______" or "I am tired of my usual ______."
The options are chore, servitude, moil, travail, and pastime.
Only one of these is widely used in modern English with the exact sense given.

Concept / Approach:
The word chore is the standard English term for a small, routine job, especially one that has to be done regularly around the house, such as washing dishes, sweeping, or cooking. Servitude refers to the condition of being a servant or slave, moil and travail refer to hard, often exhausting work, and pastime means an activity done for enjoyment, not duty. Thus, only chore accurately matches the idea of a routine household task.

Step-by-Step Solution:
Step 1: Focus on the key words "routine task" and "especially a household one". Step 2: Recall that common phrases include "household chores" and "daily chores" to describe regular domestic duties. Step 3: Option A Chore exactly fits this use; it is the standard dictionary definition. Step 4: Option B Servitude describes the state of being forced to serve another person and is much stronger and broader than a simple routine task. Step 5: Option C Moil means to work hard or toil, but it does not specifically refer to routine household duties. Step 6: Option D Travail refers to painful or laborious effort, often in the context of great hardship, not small daily tasks. Step 7: Option E Pastime refers to activities done for fun or relaxation, which is almost the opposite of an unwanted routine duty.

Verification / Alternative check:
Insert each word into sample sentences: "She spent the morning doing household chores" sounds perfectly natural. "She spent the morning doing household servitude" or "household moil" are awkward and uncommon. "Household pastimes" suggests hobbies, not duties. In everyday speech and writing, chore is almost always the word used for routine household tasks, confirming it as the correct answer.

Why Other Options Are Wrong:
Option B Servitude emphasises a condition of slavery or forced labour and is too strong and general for ordinary daily tasks.
Option C Moil suggests drudgery or toil but is not specifically tied to routine household work and is rarely used in modern conversation.
Option D Travail is used for intense labour or suffering, often in literary or formal contexts, and does not suit the idea of simple routine duties.
Option E Pastime refers to activities done for enjoyment, such as hobbies or games, and is the opposite of worklike tasks.

Common Pitfalls:
Because some options are uncommon or literary, candidates may be tempted to choose them assuming that a rarer word must be correct. However, one-word substitution questions often use everyday vocabulary. The safest approach is to check which word naturally fits into common phrases like "household _____" or "daily _____", and chore clearly passes that test while the other options do not.

Final Answer:
The correct one-word substitute is "Chore".