The correct answer is option 4: Lumbini. Gautama Buddha was born in Lumbini, which is now located in present-day Nepal. Lumbini is a pilgrimage site and an important place for Buddhists as it marks the birthplace of Gautama Buddha.
Option 1, Kusinagar, is not the correct answer. Kusinagar is the place where Gautama Buddha attained Parinirvana or passed away.
Option 2, Samath, is also not the correct answer. Samath is the place where Gautama Buddha gave his first sermon after attaining enlightenment.
Option 3, Bodh Gaya, is a significant place in Buddhism as it is where Gautama Buddha attained enlightenment under the Bodhi tree. However, Gautama Buddha was not born there, so it is not the correct answer.
Therefore, the correct answer is option 4, Lumbini.