Final answer:
The assembly formed by plebeians to obtain political rights is known as the Assembly of the Plebs or the Plebeian Assembly.
Step-by-step explanation:
To obtain political rights, the plebeians formed their own assembly during the Roman Republic era. This assembly is known as the C) The Assembly of the Plebs, also commonly referred to as the Plebeian Assembly. This group was crucial in allowing plebeians to exercise some degree of political power, especially as it elected tribunes who could veto actions they deemed harmful to plebeian interests. Over time, the Plebeian Assembly gained significant powers, such as enacting laws that would apply to all Roman citizens, making it an essential institution in the struggle of the plebeians for equality with the patrician class.