  A topological space $Y$ has the property (B) of Banakh if there is a
countable family $\{A_n:n\in \mathbb{N}\}$ of closed nowhere dense subsets of
$Y$ absorbing all compact subsets of $Y$. In this note we show that the space
$C_p(X)$ of continuous real-valued functions on a Tychonoff space $X$ with the
topology of pointwise convergence, fails to satisfy the property (B) if and
only if the space $X$ has the following property $(\kappa)$: every sequence of
disjoint finite subsets of $X$ has a subsequence with point--finite open
expansion. Additionally, we provide an analogous characterization for the
compact--open topology on $C(X)$. Finally, we give examples of Tychonoff spaces
$X$ whose all bounded subsets are finite, yet $X$ fails to have the property
$(\kappa)$. This answers a question of Tkachuk.
