Determine whether or not the situation describes a function. Give a reason for your answer.The letter grade in this course is a function of your numerical grade.a.No, it is not a function. Each letter grade corresponds to one numerical grade.b.No, it is not a function. Each numerical grade corresponds to one letter grade.c.Yes, it is a function. Each numerical grade corresponds to one letter grade.d.Yes, it is a function. Each letter grade corresponds to one numerical grade.