20 points plus brainliest !

which best describes cosmic microwave background radiation?

radiation thought to exist but not yet measured
radiation predicted to exist in millions of years
radiation that existed before the big bang
leftover radiation from the big bang

True or false: (a) the strings of little red dots represent carbohydrates. (b) the model is called a bilayer because there are two main types of molecules present, lipids and proteins. (c) the many black lines represent amino acid tails. (d) this model shows membrane transport. (e) the blue ovals are hydrophobic. (f) the blue ovals represent phospholipid heads.