I really need some help with my physics homework please help me

1. the crest of any wave can be replaced with a series of what?
a.equally spaced wave sources that are in step with each other
b. equally spaced wave sources that interfere with each other
c. unequally spaced wave sources that are in step with each other
d. unequally spaced wave sources that interfere with each other

which of the following is correct regarding sunlight?
a. it reaches us only after the sun has actually risen.
b. it continues to reach us after the sun has actually set
c. it stops reaching us before the sun has actually set
d. it corresponds exactly to sunrise and sunset

if you can help me i would be really grateful... thankyou

1. a) Because for waves to constructively interfere (crest) you need the crests to be in phase (or step) and both sources a multiple of the wavelength in distance from the interference (or in this case, equally spaced works)

2. a) and b) seem to imply the same thing, that being that with respect to the actual position of the sun the light is still travelling a distance and therefore giving us a delayed view of the sun's position. I'd ask your teacher for clarification on what they mean by setting and rising.. cause I'm not sure what the hell is the difference between those two.