Of the following, what is the primary reason why a complex attack like Stuxnet could be carried out by nonstate actors today?

Hacking tools are widely available.

Attacks can be reused or can be used against multiple targets.

Exploit code is so sophisticated that it is nearly impossible to reverse engineer, ensuring that the attackers cannot be identified.

Governments are focusing on smaller, more focused attacks and thus would not compete for targets with nonstate actors.