Phototropism is when a plant moves towards the sun. Geotropism deals with gravity. It is the turning or growth movement by a plant in response to gravity. This helps the plants roots go deeper ir grow in different directions to find water.
C. Sperm is produced in a male organism by meiosis
I think it's surface area would be less than it's volume so it means it won't be able to get nutrition as needed.
hope this helps :P
I guess the answer is B !! as it has no relevance and is not an observation !!