$3.$ The primary difference between controlled and uncontrolled airspace $($as far as a pilot is concerned$)$ is:

Question $3$ options:

a$)$ Controlled airspace always requires an ATC clearance

b$)$ Controlled airspace has higher weather minimums for VFR operations

c$)$ Controlled airspace always permits VFR flight

d$)$ There is no difference between controlled and uncontrolled airspace to pilots