Some bats utilize a sound pulse with a rapidly decreasing frequency. A decreasing-frequency pulse hasA. Decreasing wavelength.B. Decreasing speed.C. Increasing wavelength.D. Increasing speed.

Key Concepts: Sound Pulse, Decreasing Frequency, Wavelength, Speed Explanation: Some bats use echolocation to navigate and find prey. They emit a sound pulse, which travels out and bounces off objects in their surroundings. The bat then listens for the echo and can determine the distance and location of objects. Some bats use sound pulses with a rapidly decreasing frequency, also known as a frequency-modulated (FM) signal. Step by Step Solution: Step 1. As the frequency of the sound pulse decreases, the wavelength increases. The formula that relates frequency and wavelength is given by λ = c/f, where λ is the wavelength, c is the speed of sound and f is the frequency. Step 2. Since the speed of sound doesn't change, the wavelength must increase as frequency decreases. Therefore, option C (Increasing wavelength) is correct. Final Answer: C. Increasing wavelength.