There are a number of ways you could do this, but since this has a heavy smell of homework about it, I won't give you any code!
The first way is to use
File.ReadAllLines[
^] and then select the second line of the string array it returns, if there is one.
The other is to create a StreamReader, then read each line sequentially in a loop using
StreamReader.ReadLine.aspx[
^] until you get to the line number you want.
The first is quick, both to code and to execute, but uses a huge amount of memory for large files. The second is slower to code and to execute, but uses a small fraction of the memory space. Your choice!