Question 6
Why is walking on ice, or on very slippery ground, difficult?
The right answer is the one marked above.
Because there is too little friction to push against, so the reaction force is small. Walking means pushing the ground backwards with your foot, and that is only possible if the foot does not slip.
With little friction, the force your foot can apply to the ground is small. A small action means a small reaction — so the force carrying you forwards is small too.
The law holds on ice just as anywhere else. What changes is not the law but the magnitude of the action. Here friction is a help, not a hindrance.