= Solution
{c}
\b[Yes, for genuine precession of a nonspherical disc.] Let its unit normal be $\mathbf n=(\sin\alpha\cos\omega t,\sin\alpha\sin\omega t,\cos\alpha)$. Its trace-free <mass quadrupole moment> has the axisymmetric form
$$
Q_{ij}=Q_0\left(n_i n_j-\frac13\delta_{ij}\right),\qquad Q_0\ne0.
$$
The $xz,yz$ entries vary at $\omega$, and $xx-yy,xy$ at $2\omega$. Their nonzero second and third <time derivatives> give an oscillating far-field <metric perturbation> and positive average radiated <power>. For $\alpha=\pi/2$ the $\omega$ terms vanish but the $2\omega$ terms remain. The precise condition is $\omega\ne0$ and $\sin\alpha\ne0$: the literal inequality $\alpha\ne0$ also allows $\alpha=\pi$, where the normal is fixed and no such <gravitational radiation> occurs. For a uniform thin disc of <mass> $M_d$ and radius $b$, $Q_0=-M_db^2/4$, confirming that it is not zero.
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