# Sequential separability on $C_p(X)$

Definition. Let $$E$$ be a topological space. Suppose that $$E$$ contains a sequence $$\{x_n\}$$ such that for every $$x\in E$$, there exists a subsequence $$\{x_{n_k}\}$$ of $$\{x_n\}$$ with $$x=\lim x_{n_k}$$. Then we say $$E$$ enjoys sequential separability.

For a given topological space $$X$$, let $$C_p(X)$$ be the space of continuous functions on $$X$$ endowed with the point-wise topology. It is proved that $$C_p(X)$$ is separable iff $$X$$ is separably submetrizable (see this paper).

Question.
$$C_p(X) ~\textrm{is sequentially separable} \Leftrightarrow X=?$$