Option a is the correct answer. Statement 1 is correct: Bodhisattas, in Mahayana Buddhism, are regarded as beings who have taken a vow to attain enlightenment and assist all sentient beings in their liberation from suffering. They are seen as embodying compassion and are actively engaged in accumulating merit through their selfless actions and efforts to benefit others. Statement 2 is incorrect: Bodhisattvas postpone their own Nibbana until they have helped all other beings achieve it. This is called the "great vehicle" (mahāyāna) of compassion and wisdom.