The atomic numbers of elements $\underline {A}, \underline {B}, \underline {C}$ and $\underline {D}$ are $z-1,z,z+=1$ and $z+2$ respectively. If '$\underline {B}$' is a noble gas, choose the correct answers from the following statements :

Question

(a) '$\underline {A}$' has higher electron affinity.

(b)  '$\underline {C}$' exists in +2 oxidation state.

(c)  '$\underline {D}$' is an alkaline Earth metal.

(1) (a) and (b)

(2) (b) and (c)

(3) (a) and (c)

(4) (a),(b) and (c)