The function K concatenates s1, " and ", and s2 to output without adding any line breaks or separators between function calls. When K("sign", "horse") is called the first time, it outputs "sign and horse". When called the second time, it immediately appends "sign and horse" to the existing output. Since there are no newline characters or spaces inserted between consecutive function calls, the outputs are concatenated directly, resulting in "sign and horsesign and horse".

A. Includes an extra " and " between the two calls, which the function doesn't add.

C. Shows output from only one function call, not two.

D. Shows output from only one function call, not two.

E. Includes a space between the two function call outputs, which isn't added by the function.

- Gaddis, T. (2019). Starting Out with Programming Logic and Design (5th ed.). Pearson. Chapter 6: Functions, pp. 234-237 (Function output concatenation)

- Sebesta, R. W. (2016). Concepts of Programming Languages (11th ed.). Pearson. Chapter 9: Subprograms, Section 9.2, pp. 391-393 (Function execution and output handling)

- MIT OpenCourseWare. (2011). 6.00SC Introduction to Computer Science and Programming. Lecture 4: Functions. https://ocw.mit.edu/courses/6-00sc-introduction-to-computer-science-and-programming-spring-2011/