Would it be better for me to have a c-section now at 35 weeks?

I am 35 weeks with twins. they are breech/transverse so that is the reason for the c-section. I have been going to a high risk clinic because baby b is not getting enough blood flow through the umbilical cord. my Doctor said there is most likely a knot in the cord. so i have been researching this and it is making me worried.If there is a knot in the cord this could eventually cut off baby b supply of oxygen. there would be no way for me to tell because i can not tell which baby is moving at any time, so baby b could have decreased fetal movement and i would never know until it is too late. i am having 2 nst a week and a ultrasound with doc appt. But what if something happens in between visits? would it be better for them to take the babies out now rather then risk baby b,s life?