What does IDD preach about software development activities? I- They should be periodically revisited. II- They should be done only once. III- They...

What does IDD preach about software development activities?

I- They should be periodically revisited.
II- They should be done only once.
III- They should be done without any planning.
a) Only I is correct.
b) Only II is correct.
c) Only III is correct.
d) I and II are correct.
e) I and III are correct.