Here's a problem to solve: Both euglenas and volvox are classified as plant-like protists. But volvox has more structures in common with plants than euglenas do. Which structure found in plant cells is also found in volvox but not in euglenas?

Among the 4 following options, which is the correct answer?

- A: eyespot
 
- B: cell wall
 
- C: chloroplast
 
- D: central vacuole
 