Messenger RNA:

a. is the type of RNA that turns over most quickly in the cell.
b. in eukaryotes has a 5' cap added during posttranscriptional modification.
c. is the most abundant form of RNA.
d. is found only in the cytoplasm.
e. in all cells is initially formed as a large precurs

option B

Explanation: the RNA formed from the DNA after transcription in eukaryotes is the premRNA which undergoes some posttranscriptional modifications such as splicing, addition of the 5' cap and addition of poly A tail at the 3' end to give rise to the mRNA after transcription.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.