What is a likely reason for Dr. S. Ramadoss's retirement from politics at his 88th birthday?

Dr. S. Ramadoss announced his complete retirement from political life on his 88th birthday.

• Option 1: He had reached the age of 90
• Option 2: The party he led is still active
• Option 3: He will be retiring for health reasons
• Option 4: His son Anbumani has taken over full party control already