The correct option is A your
The determiner is an important noun modifier which provides introductions and provides context to a noun, often in terms of quantity and possession. Determiners in English precede a noun or noun phrase and include articles, demonstratives, quantifiers and possessives.
When referring to an entity that belongs to another, we can use possessives. My, your, their, and its are a few examples.
In this sentence, we have to use the possessive 'your' before gadget.