A. Keywords
B. Comments
C. Control structures
D. Blocks
View Answer B. Comments
Explanation
Comments are used to document a program. Comments are not executed by the computer, which means that they do not affect any other code in the program. This makes it easy for programmers to write comments as a way of organizing their thoughts about the code. Comments can be used to explain why certain choices were made when writing a program or what we expected some lines of code might do without actually running them.