I am having difficulty undrstanding the theory behind this question.
When an acrobat hangs motionless from a pair of rings:
a.she has no measurable weight.
b.her weight depends on the angles the ropes make with the ceiling.
c.her weight is reduced by the upward force the rings exert on her.
d.her weight is increased by the upward force the rings exert on her.
e.she exerts a gravitational force on the Earth that is equal to the sum of the forces the rings exert on her.
The weight of an object is equal to the gravitational force exerted on that object. Since this acrobat is hanging at equilibrium (The acrobat is clearly NOT acceleration.) opposite forces must be equal. Therefore, the upward forces of the two rings upward on the acrobat must be exactly equal to the gravitational force acting downward on the acrobat.