Which of the following statements are correct?

A. The process of adding an electron to a neutral gaseous atom is always exothermic.

B. The process of removing an electron from an isolated gaseous atom is always endothermic.

C. The $1^{\text {st }}$ ionization energy of boron is less than that of beryllium.

D. The electronegativity of C is 2.5 in $\mathrm{CH}_4$ and $\mathrm{CCl}_4$

E. Li is the most electropositive among elements of group I.

Choose the correct answer from the options given below:

$$ \text {Identify }[\mathrm{A}],[\mathrm{B}] \text { and }[\mathrm{C}] \text {, respectively in the following reaction sequence : } $$

$$ \text { Match the LIST-I with LIST-II } $$

$$ \text { Choose the correct answer from the options given below: } $$