Question

cnidaria - shape of life
where do jellyfish thrive?
deep underground caves
freshwater lakes
upper ocean and deeper reaches
polar ice shelves

Explanation:

Jellyfish are marine animals. Deep underground caves lack the aquatic environment they need. Freshwater lakes are not their typical habitat as they are mainly marine. Polar ice shelves have extreme cold and limited suitable conditions. Jellyfish are commonly found in the upper ocean and can also inhabit deeper reaches of the ocean where there is water, food (like plankton), and suitable physical - chemical conditions (such as salinity levels in the ocean).

Answer:

Upper ocean and deeper reaches