Im giving brainliest :D Which of the following best describes how the boy is able to flex his muscles?

As the boy bends his arm, the triceps muscles contract and extend.

As the boy bends his forearm, the biceps muscles contract and bunch up.

As the boy flexes his arm muscles, both the biceps and triceps muscles contract at the same time.

As the boy moves his forearm, both the biceps and triceps muscles relax at the same time.

Hiv is inactivated in the laboratory after a few minutes of sitting at room temperature, but the flu virus is still active after sitting for several hours. what are the practical consequences of these findings? a) hiv can be transmitted more easily from person to person than the flu virusb) the flu virus can be transmitted more easily from person to person than hivc) this property of hiv makes it more likely to be a pandemic than the flu virusd) disinfecting surfaces is more important to reduce the spread of hiv than the flu