In the following passage, some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives.
Cyber security has ________________interesting parallel to terrorism. _________________ are asymmetric. Ensuring security of data, information, and communication is considerably harder than hacking into a system. The attacker has an inherent ________________ in both conventional terrorism and cyber attacks. In the case _________________ statesponsored attacks, the challenges are of a much ________________ magnitude.