During a third trimester ultrasound, what would a doctor expect to observe in a fetus

A. initial development of organs

B. response to noise and light

C. presence of a tail-like structure

D. the first heartbeat

solvent

happy to

pls mark as brainliest

chemical weathering

explanation:

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs