Which of the following statements is false regarding viroids?

Symbiotic association between fungi and algae are called $ . . . . . . $.

The protein of capsomeres is made up of

$A$ scientist $X$ demonstrated that the extract of infected plants of $Y$ could cause infection in healthy plants and called the fluid as "Contagium vivum fluidum". Identify $X$ and $Y$.

Lichens are important in the studies on atmospheric pollution because they

The infectious agents made up of $RNA$ only are