Transformations · Challenge problem

Consider these five compositions of two transformations of the plane: (1) a reflection, then a translation; (2) a rotation, then a dilation with scale factor $2$; (3) a dilation with scale factor $-1$, then a rotation; (4) a dilation with scale factor $3$, then a dilation with scale factor $\dfrac13$; (5) a reflection, then a dilation with scale factor $-1$. For how many of the five is the composition GUARANTEED to preserve every distance (be an isometry)?