Which of these could most likely be used to identify a person online?

a. date the person started school
b. birthplace
c. favorite color
d. student identification number

Hey there!

When answering this question, think about how specific each answer choice of yours gets. 

Thousands, if not millions, of people started school on a particular day, especially considering how many people starts school in August or January in America. This cannot be used to identify a particular person on the internet. 

Again, millions (even billions) of people have been born in a particular country. While it does get more specific, into state, city, county, etc., many people will still share a particular birth place. 

Most people only know, like, 7 colors off of the top of their head. Think of how many people could possible state that one of those colors is their favorite. A lot of people. 

On the contrary, a student identification number is completely unique. Only one student in a country (or even the world, since formatting can differ between countries) can have that number. If you have access to this information, you could identify a particular person online based on this information. 

Your answer will be D. 

Hope this helped you out! :-)