The correct answer is "<span>So that they can maintain the salinity of their aquaria or aquarium to keep their aquatic animals healthy".
Salinity is referred to as the</span><span> </span>measurement<span> of </span>all of the<span> salts dissolved in bodies of water, such as oceans, lakes or rivers. Salinity is </span>generally<span> measured in </span>elements which is keeping within <span>thousands place.</span>
Stomata close is the best option
The steps are:
1. The eye cells (photoreceptors) receive light signal.
2. Transduction of light to a neural signal (nerve impulse)
3. Transmission of nerve impulses to the brain via optic nerve (afferent nerve)
4. Brain translates the signal
5. Nerve impulses is transmitted from the brain to the muscles via efferent nerves.