Which kingdom$(s)$ in Whittaker's five-kingdom classification system include living organisms?

Which of the following are the decomposers of plants?

Which one of the following statements is wrong?

Consider the following statements $(A-D)$:
$(A)$ Heterocysts are important sites for nitrogen fixation in $\text{BGA}$.
$(B)$ Cell wall of diatoms is indestructible due to presence of calcium carbonate.
$(C)$ In fungi,the cell wall is made up of chitin.
$(D)$ Algae show isogamous,anisogamous,and oogamous types of sexual reproduction.
How many of the above statement$(s)$ is/are not correct?

In which of the following,the cell wall is composed of cellulose or fungal-cellulose?

Domain Eukarya includes how many kingdoms (w.r.t. six kingdom system)?