  It is shown that the values of the ratios $\mathcal{B}(D^0\to
a_0(980)^+\pi^-)/\mathcal{B} (D^0\to a_0(980)^-\pi^+ )$ and $\mathcal{B}(D^+\to
a_0(980)^+\pi^0)/\mathcal{B} (D^+\to a_0(980)^0 \pi^+)$, recently measured by
the BESIII Collaboration, are naturally explained in the four-quark model of
the $a_0(980) $ resonance.
