Producers are typically plants, so I believe the correct answers would be 2, 3, 4.
The correct answer is d. 3.5 billion years.
Prokaryotes were the first forms of life on Earth long before simple multicellular life appeared because of their ability to withstand extreme conditions. It is believed that the first living forms were bacteria combined with archaea in the microbial mat (multi-layered sheet).
I think it is true because musicians do have to know their instrments and they have to know how to play it how to read the music or if you sing there is a lot more to it. and with athletes they have to have good strength and they have to understand whatever sport they play.