Which line of code represents a single line comment in Arduino C/C++?

• A. A statement
• B. A single line comment
• C. A function definition
• D. A bowl of cereal

Answer: (B)

In Arduino C/C++, a single-line comment is written with two forward slashes and anything after them on the same line is ignored by the compiler. This lets you add notes or explanations without affecting how the program runs. You can place the slashes after some code on the same line, like int ledPin = 13; // LED pin, or have a line that is just the comment. For comments that span multiple lines, you’d use a different form: /* ... */. The other options describe actual code constructs or are unrelated, so they aren’t comments.