Which of the following polymers has amide linkage?
Nylons are types of polyamides.
Even if you didn't know that, if you remember the monomers of nylon-6,6 which are hexamethylene diamine and adipic acid; and if you know about condensation polymerisation, you can figure out the structure of nylon-6,6
If you remember, an amide is CONH2 ... here we have CONH, this is the amide linkage.