The answer would be:
B. Sequence of the bases in DNA molecules.
Here is more about your questions:
DNA contain the instructions of the traits of an organism. Most of the organism have the same DNA but what makes each different is the sequence of the DNA. The sequence gives the instructions for the production of amino acid that will produce, which in turn determines what traits will be passed on or manifested by that individual.
The answer is A, 'a mammal' because it goes with the copulative verb 'to be', i. e., 'is'.
Clouds form as a result of the condensation of water vapor in the atmosphere. They are made of tiny droplets of water. Clouds tend to form between 3pm and 6pm because this is when the region starts to loose or has completely lost the heat form the daily sun. Water vapor will condense once temperatures are low or are decreasing.
5,996,544.
I hope this helps