  A finite group $G$ is said to be rational if every character of $G$ is
rational-valued. The Gruenberg-Kegel graph of a finite group $G$ is the
undirected graph whose vertices are the primes dividing the order of $G$ and
the edges join different primes $p$ and $q$ whenever $G$ contains an element of
order $pq$. In this paper, we complete the classification of the
Gruenberg-Kegel graphs of finite solvable rational groups initiated in
\cite{BKMdR}.
