It should be the last one, but if you can pick more than one answer then I would do the first and last one but I’m confident that it would be the last one either way :) hopefully this is helpful
Its the Eccentricity of the earth. (shape of Earth's Orbit around the sun, whether it is more circular or ovular.)
Answer:
#male gametes are formed
#generative nucleus divides
#fertilization takes place
#pollen tube grows
# zygote is formed
#embryo is formed
