Which cell organelle releases oxygen?

The amyloplasts look like:

What is the part of the chloroplast other than the grana called?

Which of the following organelles is bounded by two unit membranes?

In the given figure,what does $B$ represent?

Consider the following five statements $(A$ to $E)$ with respect to the chloroplast shown below. Select the correct option stating which ones are True $(T)$ and which ones are False $(F)$.
$A$. It is impermeable and lacks porins.
$B$. It is selectively permeable,having carrier proteins for transport.
$C$. Stacked thylakoids one over other which is the site of production of assimilatory power.
$D$. Present between two grana and contains enzymes of dark reaction.
$E$. It contains enzymes for the synthesis of sugar and proteins.

$A$

$B$

$C$

$D$

$E$