Consider the following relation (capitalized letters are attribute names and lower-case letters are values)

A	B	C	D	E
a1	b2	c2	d3	e2
a1	b2	c2	d1	e4
a2	b3	c2	d1	e5
a2	b4	c5	d1	e5

1. Determine all simple functional dependencies that exist in the relation.
2. Identify all candidate keys.