In a eutrophic water body,the excessive growth of $\underline {X}$ leads to the death of $\underline {Y}$.

• A
  $X = \text{Fungi}, Y = \text{Bacteria}$
• B
  $Y = \text{Fishes}, X = \text{Water hyacinth}$
• C
  $X = \text{Algal bloom}, Y = \text{Fishes}$
• D
  $X = \text{Water hyacinth}, Y = \text{Bacteria}$