= Solution
Using the leading predictions just obtained gives
$$
\begin{array}{c|c|c}
n&n_s&r\\\hline
2&0.96721&0.13115\\
3&0.95902&0.19672\\
4&0.95082&0.26230
\end{array}
$$
The quadratic and cubic <monomial inflation potentials> satisfy the quoted interval for the <scalar spectral index>, whereas the quartic model lies below its lower endpoint. All three exceed the quoted bound on the <tensor-to-scalar ratio>. Thus
$$
\boxed{\text{All three models are excluded by the constraints quoted in the paper.}}
$$
This conclusion uses the exam's numerical bounds and the specified 60-e-fold endpoint convention, not a substitution of later observational constraints. Even a modest endpoint adjustment does not reduce the predicted $r$ by the roughly factor of two or more needed here.
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