Like is used to compare nouns
As is used to compare clauses. At same time as is used when thre is an action oerformed

Ex: Law stunets learn to think like a lawe does - wrong
Law stunets learn to think as a lawe does - right

Here in the question own land is still a goal
is an activity. so as is correct usage

Hold on...i don't get it!

I picked "A" at first because I don't see a verb in the following clause: "..., like that of earlier generations"

Don't you need a verb following an "as" statement? Which is exactly what you described in your example?

And assuming that you do need an "as" statement, why can't D be correct? Please help!

"like" is used to compare two things which have different characteristics. for example, he look like an elephant.this sentence means he is big like an elephant but he is not an elephant.
"as" is used to compare two things which have the same characteristic. for example, my dad teaches me math as a teacher. this means my dad is a math teacher, and he teaches me math.
in your question, "as" is correct because it compares the same goal of different generations.
"D" can not be an answer b/c it violate the parallel structure: " of the majority...vs of different generations.
"E" should be correct.