Why are air cored chokes used for reduced high frequency a.c ?

Question

$\begin{array}{1 1} As\; \alpha\; is\;high , L \;is\;less \\ As\; \alpha\; is\;high , L \;is\;high \\ As\; \alpha\; is\;high , L \;is\;need\;not\;be \;high \\ none\;of\;the\;above \end{array}$