Final answer:
The Roman statesman who was assassinated after advocating for reform in support of plebian rights was 4) Tiberius Gracchus.
Step-by-step explanation:
Tiberius Gracchus, along with his brother Gaius Gracchus, sought to address the social and economic issues faced by the common Roman people. Tiberius introduced a land reform bill that aimed to limit the amount of land owned by a single individual and redistribute the excess to the poor.
However, his proposed reforms faced strong opposition from the Roman Senate, as they feared the loss of their power and privileges. Tiberius Gracchus was eventually killed by a group of senators who opposed his reforms in 133 BCE. Tiberius Gracchus was the Roman statesman who was assassinated after advocating for reform in support of plebian rights. The correct answer is 4) Tiberius Gracchus.