Which do you think is the most stealthy way below of launching the malware in Windows?

a$)$ Replace the entire process running in$$svchost$.$exe$$and set it to autorun$$

b$)$ Modify the Registry and set the malware$$in CurrentVersion$/$Run and inject into Explorer.exe

c$)$ Use the original PE name and launch as a separate process

d$)$ Change the filename into clickme.exe$$and put it at an obvious location