'a', 'b', and 'c' are all reasonable statements.
Answer:

Explanation:
Given:
- mass of car,

- distance of skidding after the application of brakes,

- coefficient of kinetic friction,

<u>So, the energy dissipated during the skidding of car:</u>
<em>Frictional force:</em>

where N = normal reaction by ground on the car


<em>Now from the work-energy equivalence:</em>


is the dissipated energy.
- According to Newton's Third Law of Motion, to every action, there is an equal and opposite reaction; action and reaction act on different bodies.
- Here, the action force is in the leftward direction, so the reaction will be in the opposite direction.
- If the action force is the swimmer pushing water in the leftward direction, then the reaction force is in the rightward direction.
- And the reaction force will be given by the water on the swimmer.
<u>Answer</u><u>:</u>
<u>The </u><u>reaction </u><u>force </u><u>is </u><u>the </u><u>water </u><u>pushing </u><u>the </u><u>swimmer </u><u>in </u><u>the </u><u>rightward </u><u>direction</u><u>.</u>
Hope you could get an idea from here.
Doubt clarification - use comment section.
Discrete systems are those systems in which are made up of finite component particles a which are non-homogeneously arranged such that no smooth variation exists. It is such that all constituent particles have properties which vary randomly. They are direct opposite to continuous systems, which are smooth arrangement of particles which cannot be individually taken into consideration.
Was this answer helpful