Which of the following is true about the holoenzyme in an open complex?

A)The DNA is bound mainly to the sigma-subunit.
B)There no interaction between the sigma factor and the -10 region.
C)There are two Na⁺ ions in the core enzyme .
D)Region 2.4 of the sigma-factor binds to the -35 region.
E)The DNA is bound mainly to the sigma-subunit and there no interaction between the sigma factor and the -10 region are both true.