What is the proper format for a single line comment in Karel?

This is a comment

// This is a comment

/* This is a comment

This is a comment

// This is a comment

are you sure

Apologies for the confusion. In Karel, the proper format for a single line comment is indeed "// This is a comment". The option "// This is a comment" is the correct format for a single line comment in Karel.

so is it a b c or d

My apologies for the confusion. The correct format for a single line comment in Karel is option B: "// This is a comment".