It is more difficult to walk on ice than on a concrete road because A. There is very little friction between the ice and feet pressing it B. Ice is soft when compared to concrete C. There is more friction between the ice and feer D. None of these

The correct answer is A. There is very little friction between the ice and feet pressing it.

When you walk on a concrete road, the friction between your shoes and the road surface helps you to grip the ground and keep your balance. However, when you walk on ice, there is very little friction between your shoes and the ice surface.

Option B is incorrect because ice is actually quite hard when compared to concrete. Option C is incorrect because there is actually less friction between ice and feet than between concrete and feet. Option D is incorrect because all of the other options are correct.