The correct option is B Evergreen trees do not shed their leaves all at once, whereas deciduous trees shed their leaves all at once.
Human body usually sheds only few strands of hair at a time and not all at once. This makes it look like humans are not losing hair at all. Similarly, evergreen trees do shed their leaves, but not all at once - hence, they look green throughout the year.
It is the deciduous trees that shed their leaves all at once.