What is the main difference between conversions and microconversions?

Question $7$ options:

a$)$

Microconversions are tracked separately from other conversions while conversions are not.

b$)$

Microconversions are not important to a campaign while conversions are.

c$)$

Microconversions have high value but happen slowly while conversions may or may not have high value.

d$)$

None of the above