I'm assuming its the 3rd option
The best answer is C - you want to test one independent variable (a specific environmental condition). If you are just testing 'the environment', your experiment would need to include all (possibly an unattainable amount of environmental circumstances due to the variety that exists) environmental conditions...there would not be a single testable IV and you would not come to a definite conclusion making your experiment invalid.
The job of tRNA is to read the message of nucleic acids, or nucleotides, and translate it into proteins, or amino acids. The process of making a protein from an mRNA template is called translation.
lithosphere, asthenosphere, mesosphere