Question

As an object sinks in a fluid, the buoyant force ____.

Answer 1

As an object sinks in a fluid, the buoyant force decrease.

Hope this helped.

Answer 2

Beginning when the bottom of the object first touches the water,
and as it descends and more and more of it goes under, the
buoyant force on it increases during that time.

As soon as the object is completely underwater, it doesn't matter
how deep under it is, the buoyant force on it remains the same.