A)

public void ResetAll() {
    for (int a = 0; a < myPumps.length; a++) { // loop through every pump we have
       myPumps[a].ResetGallonsSold(); // and call ResetGallonsSold on them
       }
}

B)

public double TotalSales() {
    double total = (myPumps[0].GallonsSold() + myPumps[1].GallonsSold()) * (mybaseprice + .25);
    // set total to the first 2 pumps at full service rates

    for (int a = 2; a < myPumps.length; a++) { // go through all remaining pumps (start at index 2)
       total = total + myPumps[a].GallonsSold() * mybaseprice; // add in the given pump at the base price
       }
    return total; // return the total
}

C)

public void CloseStation(PrintWriter logfile) {
    logfile.println("" + TotalSales()); // write out the TotalSales (coverted to a String) to the logfile
    ResetAll(); // reset all of the pumps to 0 (thanks to Part A!)
}