Read this: The introduction of new or equivalent deities coincided with Rome's most significant aggressive and defensive military forays. In 206 BC the Sibylline books commended the introduction of cult to the aniconic Magna Mater (Great Mother) from Pessinus, installed on the Palatine in 191 BC. The mystery cult to Bacchus followed; it was suppressed as subversive and unruly by decree of the Senate in 186 BC. Greek deities were brought within the sacred pomerium: temples were dedicated to Juventas (Hebe) in 191 BC, Diana (Artemis) in 179 BC, Mars (Ares) in 138 BC), and to Bona Dea, equivalent to Fauna, the female counterpart of the rural Faunus, supplemented by the Greek goddess Damia. Further Greek influences on cult images and types represented the Roman Penates as forms of the Greek Dioscuri. The military-political adventurers of the Later Republic introduced the Phrygian goddess Ma (identified with Roman Bellona, the Egyptian mystery-goddess Isis and Persian Mithras.)
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): In what year did the Senate declare the Bacchus subversive?
186 BC