Consider any $n$-simplex, $n \geq 2$. For each edge $(i,j)$, consider $n$-ball $B_{ij}$ such that vertices $x_i$ and $x_j$ are antipodal on this ball. Fix a point $x_0$ in the simplex. The question: is $x_0$ in at least $n$ balls?

**Some notes.** The question cannot be strengthened by claiming, for example, that there is vertex $i=i(x_0)$ such that $x_0$ is in all balls $B_{ij},j \neq i$. Also, it is not true for $n+1$ balls (there are counterexamples for both cases if $n=3$).

Just in case, $x_0$ is in ball $B_{ij}$ if and only if $\angle x_ix_0x_j \geq \pi/2$, or equivalently, vertices $x_i$ and $x_j$ are on opposite sides of the hyperplane $H_i$ that contains $x_0$ and is orthogonal to the line through $x_i$ and $x_0$ (and similarly for $H_j$).

Also, this question is a stronger version of that question (thanks to zeb for solving it).

Any help is much appreciated. Thank you.