Which of the following dns resource record types depend on the existence of a host a record in order to provide their intended function? (choose all that apply)
a.
d. mx
e. b and d
c. ptr
b. ns

idk

explanation:

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.

i think its white blood cells

i hope this