(b) 2 and 3 only
Fourth Council convened in Kashmir under the patronage of Kanishka. It resulted into division of all the Buddhists into two major sects
Sarvastivadins (popular in Kashmir and Mathura regions) and Mahasanghikas together forming the Mahayanists (followers of the Greater Vehicle),
Sthaviravadins and others forming the Hinsyanista (followers of the Lesser Vehicle),
Thus, Sthaviravadins is not part of Mahayana.
So. 1 wrong.
The Mahasanghikas gave rise to the following sects:
1.Ekavyaharikas
2 Lokottaravadins
3. Kukkuitikas
4. Bahusrutiya
5. Prajnapativadine
6. Chaitya-sailas
7. Apara- sailas
8. Uttara-sailas.
So, 2 is right, hence answer "b".