Nylon $66$ is

Which of the following polymers is used for making magnetic recording tapes?

Name the polymer used in the manufacturing of rayon.

$C_6H_6O$ (phenol) $\xrightarrow[\text{3}H_2\text{ (High temp and pressure)}]{Ni} (A)$ $\xrightarrow{Cu} (B)$ $\xrightarrow{NH_2OH} (C)$ $\xrightarrow{H^{+}} (D)$ $\xrightarrow{HO^{-}} (E)$
Product $(E)$ is

Buna-$N$ synthetic rubber is a copolymer of:

What is collodion?