Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Loss of electron from hydrogen atom results in nucleus of $$\sim 1.5 \times 10^{-3} \mathrm{pm}$$ size.

Reason R : Proton $$\left(\mathrm{H}^{+}\right)$$ always exists in combined form.

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

The starting material for convenient preparation of deuterated hydrogen peroxide ($$\mathrm{D_{2}O_{2}}$$) in :

Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R

Assertion A : Hydrogen is an environment friendly fuel.

Reason R : Atomic number of hydrogen is 1 and it is a very light element.

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