What order are signals collected from a uniform rectangular array (URA) arranged in?

Hello,

I recreated and then started modifying the monostatic pulse radar example in the phased array system toolbox (found here: http://www.mathworks.com/help/phased/examples/designing-a-basic-monostatic-pulse-radar.html?prodcode=AR&language=en)

I am trying to implement a monostatic pulse phased array radar, so I modified the antenna configuration as follows:

if true
hElement = phased.IsotropicAntennaElement(...
  'FrequencyRange' , [(fc-5e9) , (fc+5e9)]);
hant = phased.URA(...
  'Element' , hElement , 'Size' , [xElements , yElements] , ...
  'ElementSpacing' , (lambda/2) , 'Lattice' , 'Rectangular'); 
hantplatform = phased.Platform(...
  'InitialPosition' , [0 ; 0 ; 0] , ...
  'Velocity' , [0 ; 0 ; 0]);
hradiator = phased.Radiator(...
  'Sensor' , hElement , ...
  'OperatingFrequency' , fc);
hcollector = phased.Collector(...
  'Sensor' , hant , ...
  'OperatingFrequency' , fc);
end

Later, when the signals are simulated, I collect the responses:

if true
  collectedSig = step(hcollector , rsig , tgt_ang);
end

The output here, 'collectedSig', should be the signal as received by the array. collectedSig is a variable whose size is 9580 x 25. I have a 5x5 array, so I am expecting the number of columns to be 25, which it is.

My issue is I am attempting to do the beamforming by hand, by time shifting the data, but I am not sure what order the columns are in. I am assuming it is sorted in one of two ways:

Option A:

(1,1) (1,2) (1,...) (1,5) (2,1) (2,2) (2,...) (2,5), etc.

Option B:

(1,1) (2,1) (...,1) (5,1) (1,2) (2,2) (...,2) (5,2), etc.

I believe it's sorted as in Option A, but I can't tell for sure.