Protein Synthesis means to protein

Which way do the nitrogenous bases in dna pair up? a. a and g; t and c b. a and c; t and g c. a and t; g and c d. a and a; t and t; g and g; c and c

For this question look at the hydropic diagram water that is heated by the sun evaporates. select the number that represents it.

Is dna the same in every cell in the human body explain your answer