Cellulose , most important constiruent of plant cell wall is made up of

Question

$\begin{array}{1 1} \text{a. Branched chain of glucose molecules linked by } \alpha \text{ 1,6-glycosidic bond at the site of branching}\\ \text{ b.Unbranched chain of glucose molecules linked by } \alpha \text{1,4, glycosidic bond} \\ \text{c.Branched chain of glucose molecule linked by } \beta \text{1,4-glycosidic bond in a straight chain} \\ \text{d.Unbranched chain of glucose molecule linked by } \beta \text{1,4 glycosidic bond} \end{array} $