C is the answer, i know this is late but it can at least help some one else maybe
Less dense then water its self
Each system is unique, yet each interacts with the others.
Answer:
River Thames Rhine Elba Laura and Senna cut across Kemble, Oxford, Reading, Slough, London, and Southend.
Explanation:
Look at map. Hope this helped <3 ! Brainliest please? :)
Photosphere is the correct answer :) good luck!