  Let $\mathcal{C}(\mathfrak{p}^r)$ be the rational cuspidal divisor class
group of the Drinfeld modular curve $X_0(\mathfrak{p}^r)$ for a prime power
level $\mathfrak{p}^r\in \mathbb{F}_q[T]$. We relate the rational cuspidal
divisors of degree $0$ on $X_0(\mathfrak{p}^r)$ with $\Delta$-quotients, where
$\Delta$ is the Drinfeld discriminant function. As a result, we are able to
determine explicitly the structure of $\mathcal{C}(\mathfrak{p}^r)$ for
arbitrary prime $\mathfrak{p}\in \mathbb{F}_q[T]$ and $r\geq 2$.
