“…It is well known (see Theorem 1 in [9]) that the problem (K/k, G, φ) is ultrasolvable if and only if all its maximal adjoint problems are unsolvable, and, in this case, the problem (K/k, G, φ) itself is solvable. In the case of the quaternion extension (1.2) with n ⩾ 3, the maximal subgroups not containing the kernel ⟨b⟩ have the form G b 2 ,c,n−1 and G b 2 ,cb,n−1 .…”