Extract multiple columns with no duplicate data with bash on linux

Question

Hi all, i have a csv file like this: 

ecStudentID,StudentNetworkUsername,StudentName,StudentFirstName

100,ASTDTBJ001,"Andrew,Logan Connor",Logan

100,ASTDTBJ001,"Andrew,Logan Connor",Logan

101,BSTLTAN001,"Isaac,Matthew ",Matthew  

with bash how can I get column ID and first name without the duplicate. Example:

 ecStudentID,StudentFirstName

100,Logan

101,Matthew

Thank in advance