Which of the following is the correct output for the following JavaScript code:
var grade='Z';
var result;
switch(grade)
{
case'A':
result+="10";
case'B':
result+=" 9";
case'C':
result+=" 8";
default:
result+=" 0";
}
document.write(result);
a) 10
b) 17
c) 18
d) 0