Which of the following is thought to be engulfed by prokaryotes eventually leading to the development of animal cells?
a. mitochondria
b. chloroplasts
c. aerobic bacteria
d. cyanobacteria

b - the respond is innate and varies over time.

good luck!

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

my answer is the prothallium.brainliest