If a class Student has an indexer, then which of the following is the correct way to declare this indexer to make the C#.NET code snippet given below work successfully? Student s = new Student(); s[1, 2] = 35;

• class Student { int[ ] a = new int[5, 5]; public property WriteOnly int this[int i, int j] { set { a[i, j] = value; } } }
• class Student { int[ , ] a = new int[5, 5]; public int property WriteOnly { set { a[i, j] = value; } } }
• class Student { int[ , ] a = new int[5, 5]; public int this[int i, int j] { set { a[i, j] = value; } } }
• class Student { int[ , ] a = new int[5, 5]; int i, j; public int this { set { a[i, j] = value; } } }