In this sentence improvement question on correct preposition and expression, choose the best replacement for the underlined part: My uncle goes to office on bicycle or by foot.

Introduction / Context:
This question tests the learner grasp of prepositions used with modes of transport. English uses specific prepositions with different means of travel, and using the wrong preposition makes the sentence sound unnatural. The original sentence is My uncle goes to office on bicycle or by foot, which combines on bicycle and by foot. To answer correctly, we must know which preposition typically goes with bicycle and which expression is standard with foot.

Given Data / Assumptions:

• Base sentence: My uncle goes to office on bicycle or by foot.
• The underlined part likely includes the phrases on bicycle and by foot.
• Four options suggest different combinations of by and on.
• We must choose the option that uses the standard collocations in English.

Concept / Approach:
The general rule is that we use by plus a means of transport in the form of a noun without an article, such as by car, by bus, by train, by bicycle. For walking, the fixed expression is on foot, not by foot. Therefore, the natural combination in English is by bicycle or on foot. Using on with bicycle or by with foot sounds odd to native speakers. Our approach is to test each option against these known patterns and select the one that matches both.

Step-by-Step Solution:
Step 1: Identify the two means of transport: bicycle and foot, which really means walking. Step 2: Recall that the standard preposition with bicycle is by, as in He goes to work by bicycle. Step 3: Recall that the standard phrase for walking is on foot, as in She travels short distances on foot. Step 4: Combine these patterns to form the correct expression: by bicycle or on foot. Step 5: Compare this correct form with the answer options provided. Step 6: Confirm that option B My uncle goes to office by bicycle or on foot best follows normal English usage.

Verification / Alternative check:
We can verify using additional examples. Standard textbooks and grammar references provide sentences like Children often go to school by bicycle and In the city centre, many people travel on foot. Newspapers and formal writing also consistently use these forms. Forms like on bicycle or by foot rarely appear in edited English. Once we compare multiple real world examples, it becomes clear that by bicycle or on foot is the accepted and idiomatic combination. This confirms that option B is correct and that the original sentence needs improvement.

Why Other Options Are Wrong:
My uncle goes to office by bicycle or by foot: The phrase by foot is non standard and sounds unnatural compared to on foot.
My uncle goes to office on bicycle or on foot: Although on foot is correct, on bicycle is not the usual collocation; by bicycle is preferred.
No improvement: The original sentence mixes on bicycle and by foot, both of which conflict with standard idiomatic English and so cannot be considered correct in an examination.

Common Pitfalls:
Students often generalise that by can be used with any method of movement, which leads to incorrect expressions like by foot. Others may overuse on, producing forms such as on car or on train instead of by car or by train. Another source of confusion is the presence or absence of articles, for example on the bus but by bus. The safest strategy is to memorise the most important and common patterns by bicycle, by bus, on foot, and so on, and to notice them in reading practice. Over time, this habit reduces errors in sentence improvement questions based on prepositions and collocations.

Final Answer:
The most natural and grammatically correct sentence is My uncle goes to office by bicycle or on foot.