Without seeing the actual histograms, I can provide guidance based on typical trends in shoe sizes of boys in the 6th and 7th grades. Based on common observations, the most supported conclusion would usually be:
As boys get older, shoe sizes increase and the distribution remains relatively unchanged.
This conclusion reflects the general trend that as boys progress from 6th to 7th grade, their shoe sizes typically increase, but the overall distribution of shoe sizes might remain similar, with no drastic changes in their patterns or spread.
If you have specific details from the histograms—like the concentrations of shoe sizes or any outliers—it may be possible to derive a different conclusion. But based on standard expectations, the fourth option appears to be the most plausible.