Which of the following is least ionic?

The four quantum numbers for the electron in the outer most orbital of potassium (atomic no. 19) are

Identify the name reaction.

Consider the following elements.

Which of the following is/are true about $$\mathrm{A}^{\prime}, \mathrm{B}^{\prime}, \mathrm{C}^{\prime}$$ and $$\mathrm{D}^{\prime}$$ ?

A. Order of atomic radii: $$\mathrm{B}^{\prime}<\mathrm{A}^{\prime}<\mathrm{D}^{\prime}<\mathrm{C}^{\prime}$$

B. Order of metallic character: $$\mathrm{B}^{\prime}<\mathrm{A}^{\prime}<\mathrm{D}^{\prime}<\mathrm{C}^{\prime}$$

C. Size of the element: $$\mathrm{D}^{\prime}<\mathrm{C}^{\prime}<\mathrm{B}^{\prime}<\mathrm{A}^{\prime}$$

D. Order of ionic radii: $$\mathrm{B}^{\prime+}<\mathrm{A}^{1^{+}}<\mathrm{D}^{\prime+}<\mathrm{C}^{+}$$

Choose the correct answer from the options given below :