Which object will have particles with the highest average kinetic energy?

To determine which object has particles with the highest average kinetic energy, we need to consider the temperature of each object. The average kinetic energy of particles in a substance is directly related to its temperature in Kelvin.

Let's convert the temperatures provided to Kelvin:

- A. Water at 37 degrees Celsius: \( 37 + 273 = 310 \) K
- B. Water at 40 degrees Celsius: \( 40 + 273 = 313 \) K
- C. A drop of water at 90 degrees Celsius: \( 90 + 273 = 363 \) K
- D. An iceberg at 0 degrees Celsius: \( 0 + 273 = 273 \) K

Now, we can compare the temperatures in Kelvin:

- A: 310 K
- B: 313 K
- C: 363 K
- D: 273 K

The highest temperature, and thus the highest average kinetic energy, is found in option C, a drop of water at 90 degrees Celsius.

**Answer: C. a drop of water at 90 degrees Celsius**