Answer:
A
Explanation:
The question says what makes up a ticker Symbol in the US. First we need to know what a Ticker Symbol mean.
A Ticker Symbol is unique 1 to 5 abbreviation which may comprise of letters, number or both that are used by the Stock Exchange to identify a particular company or organisation. It is called a Ticker Symbol because back in the '80s, stock quotes were printed on the Ticker Tape machine and when it was done printing, it would make a tick-tock sound.