The because makes that fragment seems like there is more to come. If you remove the word because the sentence then becomes It was raining and that sounds like a complete thought
both. an invention can only be realized through first, inspiration which gives one the idea to create and second the willpower and drive to get it done.
The purpose of sharing what you have read with others is to better understand what you read and to reflect better on your opinions with others. So I’m this case, it would be number 3
