The stack of thylakoids of chloroplast is called
granum
The correct option is B.
Explanation of the correct option :
1. Chloroplast is a type of plastid which contain a green pigment called chlorophyll.
2. The membrane-bound flat sac-like structures found in chloroplasts are called thylakoids.
3. The stalk of thylakoid arranged one above another is called a granum.
Explanation of the incorrect option :
Option A :
Chloroplast contains a semi-fluid, colourless and colloidal complex called matrix through which the thylakoids run.
Option C :
Matrix is otherwise known as Stroma.
Option D :
Oxysomes are small round-shaped bodies found in mitochondrial cristae, which help in ATP synthesis.
Final answer: The stack of thylakoids of chloroplast is called a granum.