Mother Teresa devoted her life to serving poor and old people. She is widely recognized as one of the most selfless individuals in history, dedicating herself to helping those in need and making a positive impact on the world.

Mother Teresa, originally named Anjezë Gonxhe Bojaxhiu, was born on August 26, 1910, in Skopje, which is now part of North Macedonia. At the age of 18, she left home and joined the Sisters of Loreto, an Irish community of nuns with missions in India. She took the name Sister Teresa and began her journey of serving the poor and marginalized.

Heading 1: Early Life and Formation
- Mother Teresa was born in Skopje, North Macedonia, in 1910.
- At the age of 18, she joined the Sisters of Loreto and took the name Sister Teresa.

Heading 2: Missionaries of Charity
- In 1948, Mother Teresa left the Sisters of Loreto and started the Missionaries of Charity in Kolkata, India.
- The main focus of the Missionaries of Charity was to provide care and support to the poorest of the poor, including the homeless, sick, and dying.
- Mother Teresa believed that every person, regardless of their social status or background, deserved love, compassion, and dignity.

Heading 3: Impact and Recognition
- Mother Teresa's work gained international recognition and support. Her selfless dedication inspired many individuals to join her cause and contribute to her mission.
- She received numerous awards and honors, including the Nobel Peace Prize in 1979, for her extraordinary efforts in serving humanity.
- Mother Teresa's legacy continues to inspire people around the world to serve the less fortunate and make a difference in their lives.

Conclusion:
Mother Teresa's unwavering commitment to serving the poor and old people is why she is the correct answer to the question. Her life's work and dedication to the Missionaries of Charity have left an indelible mark on the world, reminding us of the importance of compassion, selflessness, and kindness towards others.