One mole of the octahedral complex compound $\mathrm{Co}\left(\mathrm{NH}_3\right)_5 \mathrm{Cl}_3$ gives 3 moles of ions on dissolution in water. One mole of the same complex reacts with excess of $\mathrm{AgNO}_3$ solution to yield two moles of $\mathrm{AgCl}_{(\mathrm{s})}$. The structure of the complex is:

Which of the following statement is true with respect to $\mathrm{H}_2 \mathrm{O}, \mathrm{NH}_3$ and $\mathrm{CH}_4$ ?

A. The central atoms of all the molecules are $\mathrm{sp}^3$ hybridized.

B. The $\mathrm{H}-\mathrm{O}-\mathrm{H}, \mathrm{H}-\mathrm{N}-\mathrm{H}$ and $\mathrm{H}-\mathrm{C}-\mathrm{H}$ angles in the above molecules are $104.5^{\circ}, 107.5^{\circ}$ and $109.5^{\circ}$, respectively.

C. The increasing order of dipole moment is $\mathrm{CH}_4<\mathrm{NH}_3<\mathrm{H}_2 \mathrm{O}$.

D. Both $\mathrm{H}_2 \mathrm{O}$ and $\mathrm{NH}_3$ are Lewis acids and $\mathrm{CH}_4$ is a Lewis base.

E. A solution of $\mathrm{NH}_3$ in $\mathrm{H}_2 \mathrm{O}$ is basic. In this solution $\mathrm{NH}_3$ and $\mathrm{H}_2 \mathrm{O}$ act as Lowry-Bronsted acid and base respectively.

Choose the correct answer from the options given below:

Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option.

Which of the following arrangements with respect to their reactivity in nucleophilic addition reaction is correct?