The correct answer is option 2, Gautamiputra Satkami, as he is widely considered to be the greatest ruler of the Satavahanas. Gautamiputra Satkami ruled from around 86 to 110 CE and is known for his military conquers and territorial expansion. He successfully repelled invasions from foreign powers, such as the Western Kshatrapas and the Sakas. Gautamiputra Satkami also promoted arts, literature, and religion during his rule. He issued many inscriptions that highlighted his achievements and praised his lineage. Additionally, he is credited with commissioning several important structures and monuments across the Satavahana empire. It is important to note that while all the other rulers mentioned in the options were significant in their own rights, Gautamiputra Satkami is generally considered to be the greatest ruler of the Satavahanas.