PLEASE HELP ASAP Lillian wonders how fast a train can move around a particular curve before it falls off of the track. Which of the following is the best way for Lillian to figure this out?

A.

Build a model train and track, and test one train going around several different curves at one speed.

B.

Drive a train along a curve at different speeds until it falls off of the track.

C.

Build a model train and track, and test different-sized trains going around one curve at the same speed.

D.

Build a model train and track, and test one train going around one curve at different speeds.