Upthrust exerted on an object immersed in a fluid does not depend on which of the following factors? 

According to Archimedes' principle, If a body is wholly or partially submerged in a fluid at rest it is acted upon by an upthrust buoyant force in the upward direction whose magnitude is equal to the weight of the fluid displaced by the body. 

$\mathrm{Upthrust}=\mathrm{\rho }\times \mathrm{g}\times \mathrm{v}$

Where $\rho$ is the density of the liquid, g is the acceleration due to gravity and v is the volume of the body.

Therefore, we can say upthrust on a body depends on the density of the liquid, the volume of the body, and acceleration due to gravity however it does not depend on the mass of the body.