Institution: জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় (JKKNIU) Exam: খ ইউনিট || জাতীয় কবি কাজী নজরুল ইসলাম বিশ্ববিদ্যালয় || 2013
Topic: Number (সংখ্যা), Subject: English Grammar (ইংরেজি গ্রামার)

Best Answer Explained in Below-:

The question "Which one is the singular?" requires us to identify which of the provided options represents a singular noun.

Let’s analyze each option:

A) **Public** - This refers to a collective group of people rather than a singular noun. It can denote a broad concept or community but does not represent one entity.

B) **Crowd** - Similar to "public," a crowd signifies a large group of individuals gathered together, again indicating pluralistic connotations.

C) **Knif** - This seems to be a misspelling of the word "knife." The correct singular form "knife" refers to a single cutting instrument. However, "knif" can be interpreted as a singular entity in certain contexts, especially if treated as a coined term in an informal or fictional setting.

D) **Mice** - This is the plural form of "mouse," which is clearly a plural noun.

In summary, while "knif" appears to be an unusual term, it stands as a singular form (albeit a potentially misspelled one) when compared to the other options, which are either groups or plural forms. Therefore, the correct answer is "C: Knif."