Complete the kingdom chart below

D

Explanation:

A is not viable as altering the Ph would affect the snails, and would not focus on how temperature affects the snails

B Expanding the tank would indeed give the snails more room to move around in , but in questions like these, you need to choose the best fit for the question. The larger tank also wouldn't really make the conclusion more valid

C Carrying out the experiment for a shorter length of time would only decrease the amount of data you would get to analyse to determine whether there was  an impact on the snails

D Using a larger number of snails would indeed make the conclusion more valid. This is because the number of snails that are tested increases the validity of a claim of a trend. If 10 snails instead of 5 snails are more active in warmer water, the validity of the claim is higher and more believable.