Step 1: Background.
Mother Teresa, a Roman Catholic nun of Albanian origin, dedicated her life to serving the poor, sick, and dying in Kolkata, India.
Step 2: Work.
She founded the Missionaries of Charity in 1950, focusing on the destitute, leprosy patients, and the homeless. Her deep compassion earned her the title “Saint of the Gutters.”
Step 3: Recognition.
She was awarded the Nobel Peace Prize in 1979 and canonized as Saint Teresa of Calcutta in 2016.
Thus, the correct answer is Mother Teresa.
\[
\boxed{\text{Mother Teresa}}
\]