The correct answer is: A. Word capitalization
Word capitalization is the use of capital letters at the beginning of each word in a sentence. It is the most common type of capitalization and is used in most writing situations.
Sentence capitalization is the use of a capital letter at the beginning of a sentence. It is also used in titles and headings.
Mixed capitalization is the use of both capital and lowercase letters in a word or phrase. It is often used in acronyms and abbreviations.
Row capitalization is the use of a capital letter at the beginning of each row in a table. It is used to make tables easier to read.
In the case of the optional label entered in the groupbox’s text property, word capitalization is the most appropriate type of capitalization to use. This is because the label is typically a short phrase or sentence that is used to identify the groupbox. Using word capitalization will make the label easier to read and understand.