Which of the following statements is not correct?

(a) The formation of intermediate arenium cation is slow while the elimination of ${\mathrm{H}}^{+}$ from this cation is fast. The former involves the removal of aromaticity while the latter restores aromaticity

(b) The $\mathrm{C}-\mathrm{D}$ bonds are stronger than $\mathrm{C}-\mathrm{H}$ bonds. In fact, the bond with the heavier isotope is slightly stronger than that with the lighter isotope.

( c) In electrophilic substitution reactions, the rate-determining step is the formation of arenium cation.

In this step, ${\mathrm{E}}^{+}$ bonds to the aromatic ring without cleavage of a $\mathrm{C}-\mathrm{H}$ bond. The latter is broken in the second step, which is fast as it restores the stable aromatic system. Since $\mathrm{C}-\mathrm{H}$ or $\mathrm{C}-\mathrm{D}$ bond is not broken in the rate-determining step, the overall rates of reaction are identical.