$-4$ is

$\sqrt{9}$ is

There are two statements given below.

I. $4$ is a natural number as well as a rational number. 

II. $0$ is a rational number but it's not a natural number. 

Choose the correct option.

There are two statements given below.

$\mathrm{I}.$ The simplest form of any rational number is always a rational number.

$\mathrm{II}.$ The simplest form of any rational number is always an integer.

Choose the correct option.

$\frac{3}{8}$ is 

State whether the statement given below is true or false.

The collection of numbers $-4,-3,-2,-1,0,1,2,3,4,...$ is called integers.

Positive integers correspond to natural numbers.

If $\frac{p}{q}$ is a rational number, then $p$ cannot be equal to zero.