The answer is B, short-term; sensory.
The short-term memory in the brain stores information temporary, 18 seconds according to research, long enough to be processed and invoke a stimulus. The information then lapses or is held longer for further processing. The information that can be stored in the short-term memory for the time mentioned above before lapsing is also limited to 5 - 9 items.
Short-term memory only persists if the information is repeatedly reintroduced into memory.