Considering grade letter calculator to determine the letter grade based on numerical mark.

(a) Fill in the blanks (------------ | 8 blanks) in the C# code below.

double mark = Convert. string letter Grade = ""; -B1---- (lblResultstext); if (mark > 85) { letterGrade "High Distinction"; } else if (mark > 75) { B2------ "Distinction"; } else if (--B3--> 60) { letterGrade "Credit"; } else -B4---- (mark > 50) { lettecscade B5---; } B6--- { letter Grade = "Fail"; } Label1. ---B7--- -B8