Which of the following would be an appropriate way to add variety to your sentences?

Where are the options for this question? I'll just have to generalize from my own knowledge, I guess.

Sentence variation, meaning that the sentences are not always the same length as one another, brings great variety to paragraphs, essays, and stories. 
The use of varying subjects keeps sentences flowing with more ease and they make them sound a lot nicer. Refrain from always starting with the same exact subject. If you read sentences like that nonstop, it sounds ugly, trust me. 

These are the main points that I could come up with, and also the most important.

Hope it helps :)

Dr.king , i would take my mental flight by egypt and i would watch god’s children in their magnificent trek from the dark dungeons of egypt through, or rather across the red sea, through the wilderness on toward the promised land.his  speech"i  have a dream" to encourage people that change will come. this  speech  was very important during the civil rights movement and was a contributing factor in the end of racial injustice in society. the  intended audience  of "i  have a dream" is white people. i hope this