The correct option is C Alara Kalama
Alara Kalama was the master of Buddha. After becoming an ascetic, Gautama Buddha went to Alara Kalama. He taught Sankhya philosophy in Vaishali to Gautama Buddha and also taught dhyana. After reaching the highest point Buddha left Alara and went to another teacher named Uddalaka Ramaputra who taught immaterial attainments to Buddha.