To solve this problem, we need to match the terms with their correct definitions. Let's analyze each term:$\newline \bullet$a. Saprophyte:$\newline$ - Saprophytes are organisms that decompose dead organic materials.$\newline$ - This matches with (ii).$\newline \bullet$b. Parasite:$\newline$ - Parasites live on living plants or animals, deriving nutrients at the host's expense.$\newline$ - This matches with (iii).$\newline \bullet$c. Lichens:$\newline$ - Lichens are a symbiotic association of algae and fungi.$\newline$ - This matches with (iv).$\newline \bullet$d. Mycorrhiza:$\newline$ - Mycorrhiza refers to the symbiotic association of fungi with plant roots.$\newline$ - This matches with (i).$\newline$Now, let's match the terms with their definitions:$\newline a \rightarrow ii, b \rightarrow iii, c \rightarrow iv, d \rightarrow i \newline$This corresponds to Option 4.