3 inches per year best represents the average rate at which infants grow in height during the first four years after birth. The correct option among all the options that are given in the question is the second option or option "b". The other choices given in the question seems quiet absurd. So by the method of elimination, one can say that option "b" is correct.
Genetic variation enables bacteria to adapt to changes in their environment. Since, bacteria reproduce asexually (binary fission), they can share genes (genetic transfer) via other mechanisms such as conjugation (exchange of genetic material through direct contact between two bacteria), transformation, and transduction(exchange of genetic material via bacteriophages).
Transformation is a process by which bacteria takes in DNA from its environment through the cell membrane.