Option 1: This option suggests that Ashvaghosha is the only Buddhist scholar among the given historical figures.

Option 2: This option suggests that Bhavabhuti, Nagarjuna, and Nagasena are all Buddhist scholars.

Option 3: This option suggests that Ashvaghosha, Nagarjuna, and Nagasena are Buddhist scholars.

Option 4: This option suggests that Ashvaghosha, Bhavabhuti, and Nagasena are Buddhist scholars.

The correct answer is option 3, which states that Ashvaghosha, Nagarjuna, and Nagasena are Buddhist scholars. This means that they are famous historical persons who were well-versed in Buddhist teachings and philosophies.

It is important to note that Bhavabhuti is not listed as a Buddhist scholar in this question. Therefore, option 2 is incorrect. Option 4 also includes Bhavabhuti, which makes it incorrect as well.

In conclusion, the correct answer is option 3, as it accurately identifies the Buddhist scholars among the given historical figures.