Option B is the incorrect statement. A d-subshell consists of five orbitals and can accommodate a maximum of 10 electrons, not 8. Therefore, the d-block in the modern periodic table has 10 columns, not 8. The other statements are correct: the p-block has 6 columns (as a p-subshell holds a maximum of 6 electrons), the number of columns in each block corresponds to the maximum electrons in that subshell, and the block indicates the azimuthal quantum number ($l$) for the last subshell that received electrons.