Improve the bracketed part of the sentence.

The other shirt (will cost) you more.

Iteration means doing something again and again, repeatedly,... 

Hence, looping is a process of repeating a method and so it is similar in meaning to Iteration.

A comparative compares a person or thing with another person or thing. A superlative compares a person or thing with the whole group of which that person or thing is a member

Comparative adjectives compare one person or thing with another and enable us to say whether a person or thing has more or less of a particular quality.

Example :: I’m more interested in music than studies, Arun is taller than Karthik.

Qualm means feeling confused, uneasiness, very doubtful and being in worry.

Hence, among the given options, Qualm is the opposite of Confidence.

'What is your Sirname?' is the correct sentence of the given sentence in English grammar.

Humble means not having or showing any feelings of superiority, self-assertiveness, or showiness.

Humble means in a modest, lowly and down-to-earth manner. Not in a aggressive, bold, self confident manner.

Hence, in the given options Bold is an antonym of Humble.

Beautiful means good looking, having pleasing personality, glamourous, charming.

Synonyms of Beautiful are handsome, attractive, alluring, cute, fair,...

Hence, in the given options Synonym of 'Beautiful' is Alluring.

The comma ( , ) is a punctuation mark in English which is most frequently used.

It is perhaps also the most abused and misused punctuation mark among all.

Like commas, semicolons indicate an audible pause — slightly longer than a comma's, but short of a period's full stop.

Rules for Semicolon ::

1. A semicolon can replace a period if the writer wishes to narrow the gap between two closely linked sentences.

2. Use a semicolon before such words and terms as namely, however, therefore, that is, i.e., for example, e.g., for instance, etc., when they introduce a complete sentence. It is also preferable to use a comma after these words and terms.

3. Avoid a semicolon when a dependent clause comes before an independent clause.

4. Use a semicolon to separate units of a series when one or more of the units contain commas.

Hence according to rule no. 2) option (C) He ate; however, he didn't sleep is correctly puctuated with a semicolon.