Institution: জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় (JKKNIU) Exam: ঙ ইউনিট || জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় || 2012
Topic: Sentence (বাক্য), Subject: English Grammar (ইংরেজি গ্রামার)

Best Answer Explained in Below-:

The correct choice among the options provided is B) "on foot." In English, when we refer to traveling or moving by walking, the idiomatic expression is to say a person traveled "on foot." This phrase implies that the person is using their feet for transportation, distinguishing it from other means of travel such as by car, train, or bus.

Option A) "by foot" is less commonly used and can sound awkward to native speakers. While the phrase might be understood, it lacks the idiomatic correctness of "on foot."

Option C) "by walking" is also grammatically correct but does not fit the simplified structure of travel descriptions as elegantly as "on foot" does. It implies the action of walking rather than the experience of traveling itself.

Option D) "own their foot" is grammatically incorrect and nonsensical in this context. The word "own" is unnecessary and does not fit with the travel context.

In summary, "on foot" is the standard phrasing that effectively communicates the means of travel by walking, making it the best answer.