Nasser's return to Egypt coincided with Husni al-Za'im's Syrian coup d'état. Its success and evident popular support among the Syrian people encouraged Nasser's revolutionary pursuits. Soon after his return, he was summoned and interrogated by Prime Minister Ibrahim Abdel Hadi regarding suspicions that he was forming a secret group of dissenting officers. According to secondhand reports, Nasser convincingly denied the allegations. Abdel Hadi was also hesitant to take drastic measures against the army, especially in front of its chief of staff, who was present during the interrogation, and subsequently released Nasser. The interrogation pushed Nasser to speed up his group's activities.
Try to answer this question if possible (otherwise reply "unanswerable"): What did the interrogation provoke Nasser to do?
speed up his group's activities