What is the output of the following function and function call?

void calculateCost(int count, float& subTotal, float taxCost);

float tax = 0.0,
subtotal = 0.0;

calculateCost(15, subtotal,tax);
cout << "The cost for 15 items is " << subtotal
<< ", and the tax for " << subtotal << " is " << tax << endl;
//end of fragment

void calculateCost(int count, float& subTotal, float taxCost)
{
if ( count < 10)
{
subTotal = count * 0.50;
}
else
{
subTotal = count * 0.20;
}
taxCost = 0.1 * subTotal;
}

a. The cost for 15 items is 3.00, and the tax for 3.00 is 0.30;
b. The cost for 15 items is 0.00, and the tax for 3.00 is 0.00;
c. The cost for 15 items is 0.00, and the tax for 3.00 is 0.30;
d. The cost for 15 items is 3.00, and the tax for 3.00 is 0.00;

d. The cost for 15 items is 3.00, and the tax for 3.00 is 0.00;