Who was the first woman to be ordained as bhikkhuni?

Mahapajapati Gotami

The correct answer is Option (3) - Mahapajapati Gotami

Soon there grew a body of disciples of the Buddha and he founded a sangha, an organisation of monks who too became teachers of dhamma. These monks lived simply, possessing only the essential requisites for survival, such as a bowl to receive food once a day from the laity. As they lived on alms, they were known as bhikkhus. Initially, only men were allowed into the sangha, but later women also came to be admitted. According to Buddhist texts, this was made possible through the mediation of Ananda, one of the Buddha’s dearest disciples, who persuaded him to allow women into the sangha. The Buddha’s foster mother, Mahapajapati Gotami was the first woman to be ordained as a bhikkhuni. Many women who entered the sangha became teachers of dhamma and went on to become theris, or respected women who had attained liberation.