The forces acting on a falling leaf are a air resistance and fluid friction. b weight and rolling friction. c gravity and static friction. d gravity and air resistance.

## Step 1<br />The problem is asking us to identify the forces acting on a falling leaf. The forces acting on a falling leaf are the forces that are in direct contact with the leaf and the forces that are acting on the leaf due to the environment.<br /><br />## Step 2<br />The forces acting on a falling leaf are gravity and air resistance. Gravity is the force that pulls the leaf towards the ground. Air resistance is the force that opposes the motion of the leaf through the air.<br /><br />## Step 3<br />The other options are incorrect because they include forces that are not acting on a falling leaf. For example, rolling friction is a force that acts on objects that are rolling, not falling. Static friction is a force that acts on objects that are at rest, not falling. Fluid friction is a force that acts on objects that are moving through a fluid, not air.