text: function largestOfFour(arr) {
    var largest = [];
    
    arr.reduce(function(agg, cval){
      var biggest = cval.reduce(function(agg2, cval2) {
        if (agg2 < cval2){ 
          return cval2;
        } 
        return agg2; 
      });
      
      largest.push(biggest);
  
    }, arr[0]);
    
    return largest;
  }
  