Final answer:
Only Jesus had twelve disciples as clearly described in the New Testament, whereas Mithras, though having companions and a structured following, is not documented to have had twelve disciples.
Step-by-step explanation:
The question pertains to the similarities between Jesus and Mithras in regards to their respective followers or disciples. For Jesus, the New Testament clearly states that he had twelve disciples, known as the apostles. However, there is no substantial evidence that supports Mithras having twelve disciples in the same manner. The Mithraic cult did have ranks and grades within its structure, and Mithras was often depicted with two companions, Cautes and Cautopates, but they were not paralleled as a group of twelve disciples.
In conclusion, the number of disciples or followers closely associated with Mithras is not categorically defined as twelve as it is for Jesus. Therefore, based on the information provided, the correct answer is: Option 3: Only Jesus had twelve disciples.