$3$A$)$ Create a class Student with data members name, mark, and Id$.$ Use a suitable constructor to

initialize the student object. Write a program to write five student objects into a student.txt file. Also,

read the contents of the student.txt file and display only the student with more than $80$ marks.

$3$B$)$ Write a multi$-$threaded program to do the following:

a$)$ Write thread writes $5$ strings to a file $-$ "Stringfile$2.$txt$"$

b$)$ Read thread reads "Stringfile$2.$txt$"$ and displays the String with maximum number of characters

and minimum number of characters among $5$ strings.

c$)$ The main thread accepts $5$ strings and display the $3$ character words present in strings.

$3$C$)$ Write the output of the following code snippets and Justify your answer.