What Type of Loop Is Shown in the Script Below

Multiple Choice

What type of loop is shown in the script below
< script type = "text/javascript" >
Var gradeValue = 0,
Total = 0,
Grade = 0;
While ( gradeValue != - 1 )
{
Total = total + gradeValue;
Grade = window.prompt( "Enter Integer Grade, -1 to Quit:" , "0" ) ;
GradeValue = parseInt( grade ) ;
}
< /script >

A) counter controlled
B) sentinel controlled
C) algorithm controlled
D) stepwise controlled