Solution
= Solution
\b[True.] The standard estimate <half-plane capacity is bounded by squared diameter> gives
$$
\operatorname{hcap}(A_n)\leq C\operatorname{diam}(A_n)^2.
$$
\b[Consequently $\operatorname{hcap}(A_n)\to\infty$ forces $\operatorname{diam}(A_n)\to\infty$.]