Archer, a professional hacker, is launching eccouncil video

Full Certification Question

Archer, a professional hacker, is launching a few attacks on a target organization. In this process, he exploited a vulnerability found in all Intel and ARM processors deployed by Apple to trick a process into accessing out-of-bounds memory by exploiting CPU optimization mechanisms such as speculative execution. Which of the following vulnerabilities was exploited by Archer in the above scenario?