Punctuation

Concept: Correct punctuation involves proper capitalization (for start of sentences, proper nouns) and end marks (like a period for declarative sentences). Step 1: Rules for Capitalization
The first word of a sentence should always be capitalized.
Proper nouns (specific names of people, places, countries, cities, organizations, etc.) should always be capitalized. Step 2: Rules for End Punctuation
A declarative sentence (a statement) should end with a period (.). Step 3: Apply rules to the given unpunctuated sentence Original idea: "the capital of nepal is kathmandu"
"the" at the beginning should be "The".
"nepal" is the name of a country (proper noun), so it should be "Nepal".
"kathmandu" is the name of a city (proper noun, the capital of Nepal), so it should be "Kathmandu".
The sentence is a statement, so it should end with a period. Corrected sentence: "The Capital of Nepal is Kathmandu." (Note: "Capital" as the first word is capitalized. Whether "capital" in "capital of Nepal" needs to be capitalized is debatable; often it's lowercase unless part of a formal title. However, all options capitalize "Capital" at the start.) Step 4: Evaluate the given options
(1) The Capital of nepal is Kathmandu. "nepal" is not capitalized. Incorrect.
(2) The Capital of Nepal is kathmandu "kathmandu" is not capitalized. No period at the end. Incorrect.
(3) The Capital of Nepal is Kathmandu. "The" is capitalized. "Nepal" is capitalized. "Kathmandu" is capitalized. Ends with a period. This seems correct based on the rules.
(4) the Capital of Nepal is Kathmandu. "the" at the beginning is not capitalized. Incorrect. Therefore, option (3) "The Capital of Nepal is Kathmandu." is the correctly punctuated form.