There are some concepts in Memory:
(I) Memory for a longer period (II) Memory for a short period
There are two types of memory:
(a) Short term memory (b) Active memory
The best combination of memory concept and memory type might be:
1
(I, a); (II, a)
2
(I, b); (II, b)
3
(I, a); (II, b)
4
(I, b); (II, a)