The underground stems of some plants such as grasses, strawberry is concerned with 
a) perennation
b) vegetative propagation
c) moisture absorption
d) food assimilation
e) spread to new niches.

detailed solution

Correct option is B

Underground stems of potato, ginger, turmeric, zaminkand, Colocasia are modified to store food in them. They also act as organs of perennation to tide over conditions unfavorable for growth.Underground stems of some plants such as grass and strawberry, etc., spread to new niches and when older parts die new plants are formed hence helps in vegetative propagation. The runner helps to absorb water from the soil.Some plants of arid regions modify their stems into flattened (Opuntia), or fleshy cylindrical (Euphorbia) structures. They contain chlorophyll and carry photosynthesis hence involved in food assimilation.