Select the correct diagram of a mature embryo sac.

Filiform apparatus is a characteristic feature of ...

The embryo sac is represented by:

Identify the correct option for $P$ and $Q$ based on the number of ovules in an ovary:
$P$: Number of ovules in an ovary is one
$Q$: Number of ovules in an ovary is more than one
$\quad\quad\quad\quad P \quad\quad\quad\quad\quad\quad\quad\quad Q$
$(A)$ Papaya,Watermelon,Mango | Wheat,Paddy,Orchid
$(B)$ Wheat,Paddy,Orchid | Papaya,Watermelon,Mango
$(C)$ Wheat,Paddy,Mango | Papaya,Watermelon,Orchid
$(D)$ Papaya,Watermelon,Orchid | Wheat,Paddy,Mango

The stalk with which ovules remain attached to the placenta is called:

What do '$f$' and '$g$' represent in the given figure?