What is kinetic friction ? What is rolling friction ?

Given below are two statements:

$Statement$ $(I)$ : The limiting force of static friction depends on the area of contact and independent of materials.

$Statement$ $(II)$ : The limiting force of kinetic friction is independent of the area of contact and depends on materials.

In the light of the above statements, choose the most appropriate answer from the options given below:

A body of mass $2$ kg is moving on the ground comes to rest after some time. The coefficient of kinetic friction between the body and the ground is $0.2$. The retardation in the body is ...... $m/s^2$ 

A block of mass $10 \,kg$. moving with acceleration $2 \,m / s ^2$ on horizontal rough surface is shown in figure The value of coefficient of kinetic friction is ...........

The ratio of acceleration of blocks $A$ placed on smooth incline with block $B$ placed on rough incline is $2: 1$. The coefficient of kinetic friction between block $B$ and incline is .........

A body is moving along a rough horizontal surface with an initial velocity $6\,\,m/s.$ If the body comes to rest after travelling $9\, m$, then the coefficient of sliding friction will be