B. 2
Two concepts being tested here – the pattern of distribution of electrons and the octet rule.<span> </span>
Stuxnet virus is a malicious computer worm which was discovered for the first time in 2010. Stuxnet is used to target SCADA [Supervisory Control And Data Acquisition] system. It was the one that is responsible for the serious damage to the Iran nuclear power.
People are needed on ground for the stuxnet virus to work because, the virus requires a physical implantation in order to work. Such people are usually expert in detecting the most vulnerable spots in a system.
Answer:
The ureter carries urine from the kidney down to the bladder
