Correct ans is (C.): a a b c d e is the correct order of Output.
Take address of str =100.
Because in *str(*100) it will print "a" then, *str++ will print "a" again and increment str by 1(Now str is 101). It will print "b" and increment str by 1 again(Now str is 102). At last it will print whole string from *102 as format specifier is %s so c d e is printed.