The filament of $Mastigocladus$ $laminosus$ is

Consider the following statements regarding the major pigments and stored food in the different groups of algae and choose the correct option:
$(i)$ In Chlorophyceae,the stored food material is starch and the major pigments are chlorophyll $-a$ and $d$.
$(ii)$ In Phaeophyceae,laminarin is the stored food and major pigments are chlorophyll $-a$ and $b$.
$(iii)$ In Rhodophyceae,floridean starch is the stored food and the major pigments are chlorophyll $-a, d$ and phycoerythrin.

Mention the classes of Algae and their main characteristics.

Which of the following organisms cannot fix nitrogen?
$A.$ Azotobacter
$B.$ Oscillatoria
$C.$ Anabaena
$D.$ Volvox
$E.$ Nostoc
Choose the correct answer from the options given below:

In which of the following are Chlorophyll-$a$,Chlorophyll-$d$,and Phycoerythrin found?

Identify the given figures of algae and select the correct option.