Which of the following are an example of a trade-off in human evolution (more than one answer could be correct)?

What is the first step in the scientific method?

according to the "Deep tree" in the Nova Evolution Lab, how many million years ago humans and chimpanzees shared the last common ancestor?

Observations of the natural world independently led Wallace and Darwin to the same conclusions. But who should get credit for  the idea?

How do you make a conclusion?