How do lead and tin deviate from typical charge rules, and what charges can they form?

• A. They follow the same charge rules as all main group elements.
• B. They form only negative ions because they gain electrons.
• C. They can form +2 and +4 ions due to their ability to lose different numbers of electrons.
• D. They only form +4 ions because they are in Group 4.

Answer: (C)