(a) The correct option is (B) your weight.
You can measure the weight directly if you stand on a spring-loaded bathroom scale in a bath-room with a display. It indicates the magnitude of the force that the bathroom scale is exerting on the body. If the body is at rest, then the net vertical force will be zero and so the upward force on the body due to the platform must equal the downward force on the body due to the Earth (the weight). Therefore the scale is actually measuring your weight. Thus option (B) is correct.

(b) The correct option is (C) the force of the scale pushing up on your feet.
There is an upward force will exert on the system due to the upward acceleration of the elevator. Since you are in a stationary position, the inertia of our body always tries to keep stationary position in accordance with law of inertia. So the force of scale and floor of the elevator is pushing up on your feet in the upward direction of the elevator. Therefore, the total system will move in the upward direction. Thus the scale is measuring the force of the scale pushing up on your feet.
From the above observation we conclude that, option (C) is correct.