Question

Banana has multicostate or unicostate venation

Answer 1

Answer is unicostate venation.
Here is the explanation.

Parallel Venation: When the veins arising from mid rib or main veins, run parallel to each other towards the margin or the apex of the lamina, venation is termed as parallel venation. Leaves of monocot plants. Parallel venation is of two sub-types :
(i) Pinnate or Unicostate parallel venation : The lamina has a single prominent vein or midrib running from the base to the apex of lamina. e.g., Banana, Canna, etc
(ii) Palmate or multicostate parallel venation :
The lamina has several principal veins arising from the base and running towards the apex or margin of the lamina. Multicostate parallel venation has two forms :
(a) Convergent: The principal veins converge towards the apex, e.g., Bamboo, Grass.
(b) Divergent : The principal veins diverge towards the margin, e.g., Fan palm.