Answer:

Step-by-step explanation:
Let's analyze each answer choice. 
A. Nucleus 
- Houses the genetic material (DNA) and produces RNA 
 
B. Cytoplasm 
- Fills in space, keeps organelles in place, and chemical reactions occur here 
 
C. Vacuole 
- Stores substances, isolates toxins, helps with excretion 
 
D. Chloroplast 
- Photosynthesis occurs here 
 
Based on the functions of each organelle, we can assume the best answer is C. Vacuole. Vacuoles store substances, so these organelles would hold water.