which symbol indicates the end of a song?\na\nb\nc\nd

Brief Explanations:

In musical notation, a double - bar line with two thin lines close together (as in option D) is commonly used to indicate the end of a song. Option A seems to be an incomplete or non - standard musical symbol, option B shows musical notes and a single bar line which is used for measure division, and option C is a single bar line used for measure division as well.

Answer:

D. [The double - bar line option as shown in the image]