A sphere with density ρs and volume V is submerged in a fluid with density ρf , which exerts a buoyant force of magnitude ρfVg on the sphere. Immediately after being released from rest, the sphere moves upward with an acceleration of magnitude a . Which of the following changes would result in an acceleration with greater magnitude immediately after release? a) Releasing the sphere closer to the surface of the fluid b) Increasing the density of the fluid c) Increasing the volume of the sphere but keeping its density constant d) Increasing the air pressure at the surface of the fluid