Sensitive open map semigroups on Peano continua having a free arc

Let $X$ be a Peano continuum having a free arc and let $C^0(X)$ be the semigroup of continuous self-maps of $X$. A subsemigroup $Fsubset C^0(X)$ is said to be sensitive, if there is some constant $c>0$ such that for any nonempty open set $Usubset X$, there is some $fin F$ such that the diameter ${rm diam}(f(U))>c$. We show that if $X$ admits a sensitive commutative subsemigroup $F$ of $C^0(X)$ consisting of continuous open maps, then either $X$ is an arc, or $X$ is a circle.