In ordinary English writing, which of the following punctuation marks is used most frequently?

Introduction / Context:
Punctuation marks help readers understand the structure and rhythm of sentences in English. Some marks appear very often in everyday writing, while others are used more rarely or only in formal contexts. This question asks you to identify which punctuation mark, in typical continuous prose such as essays, articles, and stories, tends to be used most frequently.

Given Data / Assumptions:

• The context is ordinary continuous text, not lists of dates or complex code.
• We are comparing the relative frequency of common punctuation marks.
• The options include semicolon, full stop, comma, and apostrophe.
• We assume long passages of normal English prose rather than very short fragments.

Concept / Approach:
In real passages of English text, commas appear extremely often because they perform many roles: separating items in lists, setting off clauses, marking introductory phrases, and indicating slight pauses. Full stops (periods) are necessary to end sentences, but each sentence usually contains only one full stop. Inside a typical sentence, however, there may be several commas. Semicolons are relatively rare and used mostly in formal writing to link closely related independent clauses or to separate complex list items. Apostrophes show possession or contractions, but they do not appear as frequently as commas in normal paragraphs. Therefore, the punctuation mark used most frequently is the comma.

Step-by-Step Solution:
Step 1: Imagine reading a page of a newspaper article or a story and notice how often you see commas between words and phrases. Step 2: Count how many full stops appear. Each sentence has one, but some sentences are long and contain several commas before they end. Step 3: Consider how rarely you see semicolons; they usually appear only a few times in a long piece of formal writing. Step 4: Think about apostrophes, which appear with contractions like don't or possessives like the teacher's book, but usually not as often as commas. Step 5: Conclude that the comma is the most frequently used punctuation mark among the options.

Verification / Alternative check:
If you pick any random paragraph from a novel or article and quickly scan the punctuation, you will usually find that commas are scattered throughout sentences, while full stops appear only at the end of each sentence. In a paragraph with five sentences, there may be five full stops but perhaps ten or fifteen commas. Semicolons and apostrophes appear less often. Linguistic studies that count punctuation in large text corpora also show that commas are among the most common marks, supporting this intuitive observation.

Why Other Options Are Wrong:
Semicolon (;): This is wrong because the semicolon is used relatively rarely and often only in more formal or academic writing. It is far less frequent than the comma or full stop.
Full stop (period) (.): This is wrong because although every sentence ends with one, longer sentences can contain multiple commas, so commas usually outnumber full stops in extended passages.
Apostrophe mark: This is wrong because apostrophes appear only when contractions or possessives occur. In many lines of text, there may be no apostrophes at all, while commas still appear.

Common Pitfalls:
Some students quickly choose full stop because they think of sentences rather than the number of marks inside them. Others may not pay attention to real text and assume that each punctuation mark appears roughly equally. A practical way to avoid this error is simply to look at a paragraph of writing and quickly compare the visible counts: the many small curls of commas almost always stand out. Remembering that commas have many different uses across sentence structures will also help you select the right answer.

Final Answer:
The punctuation mark most frequently used in ordinary English writing is the Comma (,).