Directions: Each of these questions contains an Assertion followed by reason. Read them carefully and answer the question on the basis of following options. You have to select the one that best describes the two statements.

Assertion: Lithium is the weakest reducing agent among the alkali metals.

Reason: In alkali metals, ionisation energy decreases down the group.

Identify the correct statements about alkali metals.

A. The order of standard reduction potential $({\mathrm{M}}^{+} | \mathrm{M})$ for alkali metal ions is $\mathrm{Na} > \mathrm{Rb} > \mathrm{Li}$.

B. $\mathrm{CsI}$ is highly soluble in water.

C. Lithium carbonate is highly stable to heat.

D. Potassium dissolved in concentrated liquid ammonia is blue and paramagnetic.

E. All alkali metal hydrides are ionic solids.

Choose the correct answer from the options given below