The figure represents a solid uniform sphere of mass \( M \) and radius \( R \). A spherical cavity of radius \( r \) is at a distance \( a \) from the centre of the sphere. The gravitational field inside the cavity is (a) non-uniform (b) towards the centre of the cavity (c) directly proportional to \( a \) (d) All of these 📲PW App Link - https://bit.ly/YTAI_PWAP 🌐PW Website - https://www.pw.live