**Explanation:**

**Anion Formation:**
- Anions are formed when atoms gain electrons to achieve a stable electron configuration.
- A stable electron configuration is typically achieved by filling the valence shell with eight electrons, known as the octet rule.

**Oxygen Family:**
- The oxygen family consists of elements such as oxygen (O), sulfur (S), selenium (Se), and tellurium (Te).
- These elements have six valence electrons.
- To achieve a stable electron configuration, they tend to gain two electrons to complete their octet.
- Therefore, they readily form anions with a -2 charge, such as O^2-, S^2-, Se^2-, and Te^2-.

**Nitrogen Family:**
- The nitrogen family includes elements such as nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi).
- These elements have five valence electrons.
- To achieve a stable electron configuration, they tend to gain three electrons to complete their octet.
- However, gaining three electrons is energetically unfavorable for these elements.
- Therefore, they typically form anions with a -3 charge, such as N^3-, P^3-, As^3-, Sb^3-, and Bi^3-, but not as readily as the elements in the oxygen family.

**Halogens:**
- The halogens include elements such as fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
- These elements have seven valence electrons.
- To achieve a stable electron configuration, they tend to gain one electron to complete their octet.
- Therefore, they readily form anions with a -1 charge, such as F^-, Cl^-, Br^-, I^-, and At^-.

**Alkali Metals:**
- The alkali metals include elements such as lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs).
- These elements have one valence electron.
- To achieve a stable electron configuration, they tend to lose this valence electron and form cations with a +1 charge.
- Therefore, they do not readily form anions.

**Conclusion:**
- Among the given options, the halogens (option C) will form anions most readily.
- This is because they have seven valence electrons and only need to gain one electron to complete their octet.
- The other elements in the oxygen family and nitrogen family also form anions, but not as readily as the halogens.
- The alkali metals do not readily form anions; instead, they tend to form cations by losing their valence electron.