Im 90% sure the answer is b) chemoreceptors
Solute potential of a solution is calculated using the formula,
Ψ
Where,
Ψ
is the solute potential of the solution,
<em>i</em> is the degree to which the solute ionizes(ionization constant) in solution = 1, as sucrose is a nonelectrolyte.
C is the concentration of the solution in molarity = 0.5 M
R is the gas constant or the pressure constant = 0.0831 L.bar/(mol.K)
T is the temperature in Kelvin scale = 
Calculating the solute potential of the surrounding sucrose solution:
Ψ
= -(1 * 0.5 M * (0.0831 L.bar/(mol.K))* 303 K)
= 12.6 bar
Therefore, the solute potential of the surrounding solution is 12.6 bar
There are no choices, I'll assume that the Nereus in the question refers to the underwater vehicle.
Facts about the Nereus
1) It is an HROV or <span>hybrid unmanned autonomous underwater vehicle. Operated underwater but its operator is in a remote location.
2) Built and operated by WHOI or </span>Woods Hole Oceanographic Institution<span>
3) Designed to explore the deepest surveyed point of the ocean worldwide named Challenger Deep.
4) Deepest dive was at 35,768 feet of the Mariana Trench last May 2009.
5) Was lost on May 10, 2014 after it imploded due to pressure in the Kermadec Trench</span>