Vascular bundles surrounded by a sclerenchymatous bundle sheath is a feature of 

The epidermis in a dorsiventral leaf

$\left(\mathrm{a}\right)$ Cover both adaxial and abaxial surface

$\left(\mathrm{b}\right)$ Is not covered by cuticle

$\left(\mathrm{c}\right)$ Bears more stomata on the upper side

$\left(\mathrm{d}\right)$ May even lack stomata on the upper side

Which of the above statements are correct?

During water stress, the bulliform cells

(a) Become turgid

(b) Become flaccid

(c) Make the leaves curl inwards

(d) Make the leaf surface exposed

The correct option are