All plastids have essentially the same structure because

Which of the following are found in all plant cells and in euglenoids?

Which of the following statements are correct?
$(A)$ The number of chloroplasts varies from $1$ per cell in $Chlamydomonas$, a green alga, to $20-40$ per cell in the mesophyll.
$(B)$ Out of the two membranes of chloroplasts and mitochondria, the inner membrane is relatively less permeable.
$(C)$ Thylakoids are arranged in stacks like the piles of coins called grana (singular: granum) or the intergranal thylakoids.
$(D)$ The stroma of the chloroplast contains enzymes required for the synthesis of carbohydrates and proteins.

The term $chromatophore$ was coined by

Which of the following is not a shape of the chloroplast?

What is common between chloroplasts,chromoplasts,and leucoplasts?