The correct answer is option (d) i and ii. Let's analyze each of the statements to understand why this is the correct answer: I. Electromagnetic waves are transverse waves. This statement is true. Electromagnetic waves are transverse, meaning that the oscillation of electric and magnetic fields occurs perpendicular to the direction of wave propagation. II. All types of electromagnetic waves propagate at the same speed in a vacuum. This statement is also true. In a vacuum, all electromagnetic waves propagate at the speed of light, which is approximately 299,792,458 meters per second (m/s). III. Electromagnetic waves cannot be polarized. This statement is false. Electromagnetic waves can be polarized. Polarization is a phenomenon that describes the orientation of the plane of oscillation of electric and magnetic fields. For example, polarized sunglasses are used to block horizontally polarized light, reducing glare. IV. The frequency of all types of electromagnetic waves is the same in a vacuum. This statement is false. The frequency of electromagnetic waves varies widely, distinguishing different types of electromagnetic radiation such as radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. The speed of light in a vacuum is constant, but the frequency and wavelength can vary. Therefore, only statements I and II are true, making option (d) the correct answer.