Incorrect. In isobilateral leaves (like in most monocots), stomata are typically present on both surfaces (both adaxial and abaxial).

Incorrect. When bulliform cells become turgid, they cause the leaf to spread out, exposing the leaf surface, but this is not to minimize water loss. When they become flaccid, they cause the leaf to curl, which helps to minimize water loss.
Incorrect. Parallel venation in monocot leaves generally results in vascular bundles of similar sizes, especially when viewed in vertical sections.
Incorrect. Bulliform cells are generally present on the adaxial surface of isobilateral leaves.
(E) Correct. In isobilateral leaves, the mesophyll typically does not differentiate extensively into palisade and spongy parenchyma. The cells are more uniformly chlorenchymatous.

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